diff --git a/src/Symfony/Bridge/Doctrine/Test/TestRepositoryFactory.php b/src/Symfony/Bridge/Doctrine/Test/TestRepositoryFactory.php
index e7df3702eb..f6ac1eedda 100644
--- a/src/Symfony/Bridge/Doctrine/Test/TestRepositoryFactory.php
+++ b/src/Symfony/Bridge/Doctrine/Test/TestRepositoryFactory.php
@@ -29,7 +29,7 @@ final class TestRepositoryFactory implements RepositoryFactory
     /**
      * {@inheritdoc}
      */
-    public function getRepository(EntityManagerInterface $entityManager, $entityName)
+    public function getRepository(EntityManagerInterface $entityManager, $entityName): ObjectRepository
     {
         $repositoryHash = $this->getRepositoryHash($entityManager, $entityName);
 
@@ -47,10 +47,7 @@ final class TestRepositoryFactory implements RepositoryFactory
         $this->repositoryList[$repositoryHash] = $repository;
     }
 
-    /**
-     * @return ObjectRepository
-     */
-    private function createRepository(EntityManagerInterface $entityManager, $entityName)
+    private function createRepository(EntityManagerInterface $entityManager, $entityName): ObjectRepository
     {
         /* @var $metadata ClassMetadata */
         $metadata = $entityManager->getClassMetadata($entityName);
@@ -59,7 +56,7 @@ final class TestRepositoryFactory implements RepositoryFactory
         return new $repositoryClassName($entityManager, $metadata);
     }
 
-    private function getRepositoryHash(EntityManagerInterface $entityManager, $entityName)
+    private function getRepositoryHash(EntityManagerInterface $entityManager, $entityName): string
     {
         return $entityManager->getClassMetadata($entityName)->getName().spl_object_hash($entityManager);
     }
diff --git a/src/Symfony/Bridge/Monolog/Handler/ChromePhpHandler.php b/src/Symfony/Bridge/Monolog/Handler/ChromePhpHandler.php
index 3a9f478363..f7a95ebe15 100644
--- a/src/Symfony/Bridge/Monolog/Handler/ChromePhpHandler.php
+++ b/src/Symfony/Bridge/Monolog/Handler/ChromePhpHandler.php
@@ -73,7 +73,7 @@ class ChromePhpHandler extends BaseChromePhpHandler
     /**
      * Override default behavior since we check it in onKernelResponse.
      */
-    protected function headersAccepted()
+    protected function headersAccepted(): bool
     {
         return true;
     }
diff --git a/src/Symfony/Bridge/Monolog/Handler/FirePHPHandler.php b/src/Symfony/Bridge/Monolog/Handler/FirePHPHandler.php
index be50c3f8ca..48252c4f03 100644
--- a/src/Symfony/Bridge/Monolog/Handler/FirePHPHandler.php
+++ b/src/Symfony/Bridge/Monolog/Handler/FirePHPHandler.php
@@ -75,7 +75,7 @@ class FirePHPHandler extends BaseFirePHPHandler
     /**
      * Override default behavior since we check the user agent in onKernelResponse.
      */
-    protected function headersAccepted()
+    protected function headersAccepted(): bool
     {
         return true;
     }
diff --git a/src/Symfony/Bridge/Monolog/Processor/RouteProcessor.php b/src/Symfony/Bridge/Monolog/Processor/RouteProcessor.php
index 7453f3716c..23b95d9b85 100644
--- a/src/Symfony/Bridge/Monolog/Processor/RouteProcessor.php
+++ b/src/Symfony/Bridge/Monolog/Processor/RouteProcessor.php
@@ -35,7 +35,7 @@ class RouteProcessor implements EventSubscriberInterface, ResetInterface
         $this->reset();
     }
 
-    public function __invoke(array $records)
+    public function __invoke(array $records): array
     {
         if ($this->routeData && !isset($records['extra']['requests'])) {
             $records['extra']['requests'] = array_values($this->routeData);
@@ -78,7 +78,7 @@ class RouteProcessor implements EventSubscriberInterface, ResetInterface
         unset($this->routeData[$requestId]);
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::REQUEST => ['addRouteData', 1],
diff --git a/src/Symfony/Bridge/Monolog/Processor/WebProcessor.php b/src/Symfony/Bridge/Monolog/Processor/WebProcessor.php
index dfb2c2f2d4..3916379dbc 100644
--- a/src/Symfony/Bridge/Monolog/Processor/WebProcessor.php
+++ b/src/Symfony/Bridge/Monolog/Processor/WebProcessor.php
@@ -39,7 +39,7 @@ class WebProcessor extends BaseWebProcessor implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::REQUEST => ['onKernelRequest', 4096],
diff --git a/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php b/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php
index 70ca302aff..edb8bd6ae5 100644
--- a/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php
+++ b/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php
@@ -40,7 +40,7 @@ class ProxyDumper implements DumperInterface
     /**
      * {@inheritdoc}
      */
-    public function isProxyCandidate(Definition $definition)
+    public function isProxyCandidate(Definition $definition): bool
     {
         return ($definition->isLazy() || $definition->hasTag('proxy')) && $this->proxyGenerator->getProxifiedClass($definition);
     }
@@ -48,7 +48,7 @@ class ProxyDumper implements DumperInterface
     /**
      * {@inheritdoc}
      */
-    public function getProxyFactoryCode(Definition $definition, $id, $factoryCode = null)
+    public function getProxyFactoryCode(Definition $definition, $id, $factoryCode = null): string
     {
         $instantiation = 'return';
 
@@ -82,7 +82,7 @@ EOF;
     /**
      * {@inheritdoc}
      */
-    public function getProxyCode(Definition $definition)
+    public function getProxyCode(Definition $definition): string
     {
         $code = $this->classGenerator->generate($this->generateProxyClass($definition));
 
diff --git a/src/Symfony/Bridge/Twig/Extension/RoutingExtension.php b/src/Symfony/Bridge/Twig/Extension/RoutingExtension.php
index 67fbe8d391..cab0809129 100644
--- a/src/Symfony/Bridge/Twig/Extension/RoutingExtension.php
+++ b/src/Symfony/Bridge/Twig/Extension/RoutingExtension.php
@@ -93,7 +93,7 @@ class RoutingExtension extends AbstractExtension
      *
      * @final
      */
-    public function isUrlGenerationSafe(Node $argsNode)
+    public function isUrlGenerationSafe(Node $argsNode): array
     {
         // support named arguments
         $paramsNode = $argsNode->hasNode('parameters') ? $argsNode->getNode('parameters') : (
diff --git a/src/Symfony/Bridge/Twig/Extension/TranslationExtension.php b/src/Symfony/Bridge/Twig/Extension/TranslationExtension.php
index 7bf3bdb24e..2d90bb6556 100644
--- a/src/Symfony/Bridge/Twig/Extension/TranslationExtension.php
+++ b/src/Symfony/Bridge/Twig/Extension/TranslationExtension.php
@@ -58,7 +58,7 @@ class TranslationExtension extends AbstractExtension
     /**
      * {@inheritdoc}
      */
-    public function getFilters()
+    public function getFilters(): array
     {
         return [
             new TwigFilter('trans', [$this, 'trans']),
@@ -70,7 +70,7 @@ class TranslationExtension extends AbstractExtension
      *
      * @return AbstractTokenParser[]
      */
-    public function getTokenParsers()
+    public function getTokenParsers(): array
     {
         return [
             // {% trans %}Symfony is great!{% endtrans %}
@@ -84,17 +84,17 @@ class TranslationExtension extends AbstractExtension
     /**
      * {@inheritdoc}
      */
-    public function getNodeVisitors()
+    public function getNodeVisitors(): array
     {
         return [$this->getTranslationNodeVisitor(), new TranslationDefaultDomainNodeVisitor()];
     }
 
-    public function getTranslationNodeVisitor()
+    public function getTranslationNodeVisitor(): TranslationNodeVisitor
     {
         return $this->translationNodeVisitor ?: $this->translationNodeVisitor = new TranslationNodeVisitor();
     }
 
-    public function trans($message, array $arguments = [], $domain = null, $locale = null, $count = null)
+    public function trans($message, array $arguments = [], $domain = null, $locale = null, $count = null): string
     {
         if (null !== $count) {
             $arguments['%count%'] = $count;
@@ -106,7 +106,7 @@ class TranslationExtension extends AbstractExtension
     /**
      * {@inheritdoc}
      */
-    public function getName()
+    public function getName(): string
     {
         return 'translator';
     }
diff --git a/src/Symfony/Bridge/Twig/Mime/WrappedTemplatedEmail.php b/src/Symfony/Bridge/Twig/Mime/WrappedTemplatedEmail.php
index 7c0b585a4e..143d6be5b1 100644
--- a/src/Symfony/Bridge/Twig/Mime/WrappedTemplatedEmail.php
+++ b/src/Symfony/Bridge/Twig/Mime/WrappedTemplatedEmail.php
@@ -65,7 +65,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function setSubject(string $subject)
+    public function setSubject(string $subject): object
     {
         $this->message->subject($subject);
 
@@ -80,7 +80,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function setReturnPath(string $address)
+    public function setReturnPath(string $address): object
     {
         $this->message->returnPath($address);
 
@@ -95,7 +95,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function addFrom(string $address, string $name = null)
+    public function addFrom(string $address, string $name = null): object
     {
         $this->message->addFrom($name ? new NamedAddress($address, $name) : new Address($address));
 
@@ -113,7 +113,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function addReplyTo(string $address)
+    public function addReplyTo(string $address): object
     {
         $this->message->addReplyTo($address);
 
@@ -131,7 +131,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function addTo(string $address, string $name = null)
+    public function addTo(string $address, string $name = null): object
     {
         $this->message->addTo($name ? new NamedAddress($address, $name) : new Address($address));
 
@@ -149,7 +149,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function addCc(string $address, string $name = null)
+    public function addCc(string $address, string $name = null): object
     {
         $this->message->addCc($name ? new NamedAddress($address, $name) : new Address($address));
 
@@ -167,7 +167,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function addBcc(string $address, string $name = null)
+    public function addBcc(string $address, string $name = null): object
     {
         $this->message->addBcc($name ? new NamedAddress($address, $name) : new Address($address));
 
@@ -185,7 +185,7 @@ final class WrappedTemplatedEmail
     /**
      * @return $this
      */
-    public function setPriority(int $priority)
+    public function setPriority(int $priority): object
     {
         $this->message->setPriority($priority);
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/RouterCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/RouterCacheWarmer.php
index 6450eb33d7..6db604fa85 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/RouterCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/RouterCacheWarmer.php
@@ -57,7 +57,7 @@ class RouterCacheWarmer implements CacheWarmerInterface, ServiceSubscriberInterf
      *
      * @return bool always true
      */
-    public function isOptional()
+    public function isOptional(): bool
     {
         return true;
     }
@@ -65,7 +65,7 @@ class RouterCacheWarmer implements CacheWarmerInterface, ServiceSubscriberInterf
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedServices()
+    public static function getSubscribedServices(): array
     {
         return [
             'router' => RouterInterface::class,
diff --git a/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php b/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php
index 5feacb6492..19130b237c 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php
@@ -258,7 +258,7 @@ EOT
         return self::METHOD_COPY;
     }
 
-    private function getPublicDirectory(ContainerInterface $container)
+    private function getPublicDirectory(ContainerInterface $container): string
     {
         $defaultPublicDir = 'public';
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/Command/ContainerDebugCommand.php b/src/Symfony/Bundle/FrameworkBundle/Command/ContainerDebugCommand.php
index bfd88b09d5..f17b037505 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Command/ContainerDebugCommand.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Command/ContainerDebugCommand.php
@@ -208,11 +208,9 @@ EOF
     /**
      * Loads the ContainerBuilder from the cache.
      *
-     * @return ContainerBuilder
-     *
      * @throws \LogicException
      */
-    protected function getContainerBuilder()
+    protected function getContainerBuilder(): ContainerBuilder
     {
         if ($this->containerBuilder) {
             return $this->containerBuilder;
diff --git a/src/Symfony/Bundle/FrameworkBundle/Controller/ControllerResolver.php b/src/Symfony/Bundle/FrameworkBundle/Controller/ControllerResolver.php
index a3d04de760..859d1c200e 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Controller/ControllerResolver.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Controller/ControllerResolver.php
@@ -24,12 +24,12 @@ class ControllerResolver extends ContainerControllerResolver
     /**
      * {@inheritdoc}
      */
-    protected function instantiateController($class)
+    protected function instantiateController($class): object
     {
         return $this->configureController(parent::instantiateController($class), $class);
     }
 
-    private function configureController($controller, string $class)
+    private function configureController($controller, string $class): object
     {
         if ($controller instanceof ContainerAwareInterface) {
             $controller->setContainer($this->container);
diff --git a/src/Symfony/Bundle/SecurityBundle/Command/UserPasswordEncoderCommand.php b/src/Symfony/Bundle/SecurityBundle/Command/UserPasswordEncoderCommand.php
index 84ad3e4c8b..248e2f013a 100644
--- a/src/Symfony/Bundle/SecurityBundle/Command/UserPasswordEncoderCommand.php
+++ b/src/Symfony/Bundle/SecurityBundle/Command/UserPasswordEncoderCommand.php
@@ -180,7 +180,7 @@ EOF
         })->setHidden(true)->setMaxAttempts(20);
     }
 
-    private function generateSalt()
+    private function generateSalt(): string
     {
         return base64_encode(random_bytes(30));
     }
diff --git a/src/Symfony/Bundle/SecurityBundle/Debug/WrappedListener.php b/src/Symfony/Bundle/SecurityBundle/Debug/WrappedListener.php
index 5c19e6aa78..3b21e0d94a 100644
--- a/src/Symfony/Bundle/SecurityBundle/Debug/WrappedListener.php
+++ b/src/Symfony/Bundle/SecurityBundle/Debug/WrappedListener.php
@@ -54,7 +54,7 @@ final class WrappedListener
         return $this->listener->{$method}(...$arguments);
     }
 
-    public function getWrappedListener()
+    public function getWrappedListener(): callable
     {
         return $this->listener;
     }
diff --git a/src/Symfony/Bundle/WebProfilerBundle/EventListener/WebDebugToolbarListener.php b/src/Symfony/Bundle/WebProfilerBundle/EventListener/WebDebugToolbarListener.php
index 85c79f6b6f..075891c81d 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/EventListener/WebDebugToolbarListener.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/EventListener/WebDebugToolbarListener.php
@@ -55,7 +55,7 @@ class WebDebugToolbarListener implements EventSubscriberInterface
         $this->cspHandler = $cspHandler;
     }
 
-    public function isEnabled()
+    public function isEnabled(): bool
     {
         return self::DISABLED !== $this->mode;
     }
@@ -136,7 +136,7 @@ class WebDebugToolbarListener implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::RESPONSE => ['onKernelResponse', -128],
diff --git a/src/Symfony/Component/BrowserKit/HttpBrowser.php b/src/Symfony/Component/BrowserKit/HttpBrowser.php
index 7492e58907..d36cf23712 100644
--- a/src/Symfony/Component/BrowserKit/HttpBrowser.php
+++ b/src/Symfony/Component/BrowserKit/HttpBrowser.php
@@ -41,7 +41,7 @@ class HttpBrowser extends AbstractBrowser
         parent::__construct([], $history, $cookieJar);
     }
 
-    protected function doRequest($request)
+    protected function doRequest($request): Response
     {
         $headers = $this->getHeaders($request);
         [$body, $extraHeaders] = $this->getBodyAndExtraHeaders($request);
diff --git a/src/Symfony/Component/BrowserKit/Response.php b/src/Symfony/Component/BrowserKit/Response.php
index bc1da98537..376bd78df4 100644
--- a/src/Symfony/Component/BrowserKit/Response.php
+++ b/src/Symfony/Component/BrowserKit/Response.php
@@ -40,7 +40,7 @@ final class Response
      *
      * @return string The response with headers and content
      */
-    public function __toString()
+    public function __toString(): string
     {
         $headers = '';
         foreach ($this->headers as $name => $value) {
@@ -61,7 +61,7 @@ final class Response
      *
      * @return string The response content
      */
-    public function getContent()
+    public function getContent(): string
     {
         return $this->content;
     }
@@ -76,7 +76,7 @@ final class Response
      *
      * @return array The response headers
      */
-    public function getHeaders()
+    public function getHeaders(): array
     {
         return $this->headers;
     }
diff --git a/src/Symfony/Component/BrowserKit/Tests/HttpBrowserTest.php b/src/Symfony/Component/BrowserKit/Tests/HttpBrowserTest.php
index ef6fac4f29..64594d503f 100644
--- a/src/Symfony/Component/BrowserKit/Tests/HttpBrowserTest.php
+++ b/src/Symfony/Component/BrowserKit/Tests/HttpBrowserTest.php
@@ -59,7 +59,7 @@ class TestHttpClient extends HttpBrowser
         return $response;
     }
 
-    protected function doRequest($request)
+    protected function doRequest($request): Response
     {
         $response = parent::doRequest($request);
 
diff --git a/src/Symfony/Component/Cache/CacheItem.php b/src/Symfony/Component/Cache/CacheItem.php
index cd599d23d2..68b69799f0 100644
--- a/src/Symfony/Component/Cache/CacheItem.php
+++ b/src/Symfony/Component/Cache/CacheItem.php
@@ -37,7 +37,7 @@ final class CacheItem implements ItemInterface
     /**
      * {@inheritdoc}
      */
-    public function getKey()
+    public function getKey(): string
     {
         return $this->key;
     }
@@ -53,7 +53,7 @@ final class CacheItem implements ItemInterface
     /**
      * {@inheritdoc}
      */
-    public function isHit()
+    public function isHit(): bool
     {
         return $this->isHit;
     }
@@ -145,11 +145,9 @@ final class CacheItem implements ItemInterface
      *
      * @param string $key The key to validate
      *
-     * @return string
-     *
      * @throws InvalidArgumentException When $key is not valid
      */
-    public static function validateKey($key)
+    public static function validateKey($key): string
     {
         if (!\is_string($key)) {
             throw new InvalidArgumentException(sprintf('Cache key must be string, "%s" given', \is_object($key) ? \get_class($key) : \gettype($key)));
diff --git a/src/Symfony/Component/Config/Definition/Processor.php b/src/Symfony/Component/Config/Definition/Processor.php
index a8c43620b9..8a1281cdf0 100644
--- a/src/Symfony/Component/Config/Definition/Processor.php
+++ b/src/Symfony/Component/Config/Definition/Processor.php
@@ -28,7 +28,7 @@ class Processor
      *
      * @return array The processed configuration
      */
-    public function process(NodeInterface $configTree, array $configs)
+    public function process(NodeInterface $configTree, array $configs): array
     {
         $currentConfig = [];
         foreach ($configs as $config) {
@@ -47,7 +47,7 @@ class Processor
      *
      * @return array The processed configuration
      */
-    public function processConfiguration(ConfigurationInterface $configuration, array $configs)
+    public function processConfiguration(ConfigurationInterface $configuration, array $configs): array
     {
         return $this->process($configuration->getConfigTreeBuilder()->buildTree(), $configs);
     }
@@ -75,7 +75,7 @@ class Processor
      *
      * @return array
      */
-    public static function normalizeConfig(array $config, string $key, string $plural = null)
+    public static function normalizeConfig(array $config, string $key, string $plural = null): array
     {
         if (null === $plural) {
             $plural = $key.'s';
diff --git a/src/Symfony/Component/Config/Resource/ClassExistenceResource.php b/src/Symfony/Component/Config/Resource/ClassExistenceResource.php
index b033dd1fac..a1a0e5464a 100644
--- a/src/Symfony/Component/Config/Resource/ClassExistenceResource.php
+++ b/src/Symfony/Component/Config/Resource/ClassExistenceResource.php
@@ -43,7 +43,7 @@ class ClassExistenceResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->resource;
     }
@@ -51,7 +51,7 @@ class ClassExistenceResource implements SelfCheckingResourceInterface
     /**
      * @return string The file path to the resource
      */
-    public function getResource()
+    public function getResource(): string
     {
         return $this->resource;
     }
@@ -61,7 +61,7 @@ class ClassExistenceResource implements SelfCheckingResourceInterface
      *
      * @throws \ReflectionException when a parent class/interface/trait is not found
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         $loaded = class_exists($this->resource, false) || interface_exists($this->resource, false) || trait_exists($this->resource, false);
 
diff --git a/src/Symfony/Component/Config/Resource/ComposerResource.php b/src/Symfony/Component/Config/Resource/ComposerResource.php
index 7e7642e35f..a727217b29 100644
--- a/src/Symfony/Component/Config/Resource/ComposerResource.php
+++ b/src/Symfony/Component/Config/Resource/ComposerResource.php
@@ -30,7 +30,7 @@ class ComposerResource implements SelfCheckingResourceInterface
         $this->vendors = self::$runtimeVendors;
     }
 
-    public function getVendors()
+    public function getVendors(): array
     {
         return array_keys($this->vendors);
     }
@@ -38,7 +38,7 @@ class ComposerResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return __CLASS__;
     }
@@ -46,7 +46,7 @@ class ComposerResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         self::refresh();
 
diff --git a/src/Symfony/Component/Config/Resource/DirectoryResource.php b/src/Symfony/Component/Config/Resource/DirectoryResource.php
index bd3240e9b2..1a28881f3f 100644
--- a/src/Symfony/Component/Config/Resource/DirectoryResource.php
+++ b/src/Symfony/Component/Config/Resource/DirectoryResource.php
@@ -42,7 +42,7 @@ class DirectoryResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return md5(serialize([$this->resource, $this->pattern]));
     }
@@ -50,17 +50,15 @@ class DirectoryResource implements SelfCheckingResourceInterface
     /**
      * @return string The file path to the resource
      */
-    public function getResource()
+    public function getResource(): string
     {
         return $this->resource;
     }
 
     /**
      * Returns the pattern to restrict monitored files.
-     *
-     * @return string|null
      */
-    public function getPattern()
+    public function getPattern(): ?string
     {
         return $this->pattern;
     }
@@ -68,7 +66,7 @@ class DirectoryResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         if (!is_dir($this->resource)) {
             return false;
diff --git a/src/Symfony/Component/Config/Resource/FileExistenceResource.php b/src/Symfony/Component/Config/Resource/FileExistenceResource.php
index 886fb403f1..ca2d2c3f79 100644
--- a/src/Symfony/Component/Config/Resource/FileExistenceResource.php
+++ b/src/Symfony/Component/Config/Resource/FileExistenceResource.php
@@ -39,7 +39,7 @@ class FileExistenceResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->resource;
     }
@@ -47,7 +47,7 @@ class FileExistenceResource implements SelfCheckingResourceInterface
     /**
      * @return string The file path to the resource
      */
-    public function getResource()
+    public function getResource(): string
     {
         return $this->resource;
     }
@@ -55,7 +55,7 @@ class FileExistenceResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         return file_exists($this->resource) === $this->exists;
     }
diff --git a/src/Symfony/Component/Config/Resource/FileResource.php b/src/Symfony/Component/Config/Resource/FileResource.php
index 6d00b2baf6..4274d07bac 100644
--- a/src/Symfony/Component/Config/Resource/FileResource.php
+++ b/src/Symfony/Component/Config/Resource/FileResource.php
@@ -44,7 +44,7 @@ class FileResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->resource;
     }
@@ -52,7 +52,7 @@ class FileResource implements SelfCheckingResourceInterface
     /**
      * @return string The canonicalized, absolute path to the resource
      */
-    public function getResource()
+    public function getResource(): string
     {
         return $this->resource;
     }
@@ -60,7 +60,7 @@ class FileResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         return false !== ($filemtime = @filemtime($this->resource)) && $filemtime <= $timestamp;
     }
diff --git a/src/Symfony/Component/Config/Resource/GlobResource.php b/src/Symfony/Component/Config/Resource/GlobResource.php
index c9e0b34734..bd29c4c274 100644
--- a/src/Symfony/Component/Config/Resource/GlobResource.php
+++ b/src/Symfony/Component/Config/Resource/GlobResource.php
@@ -52,7 +52,7 @@ class GlobResource implements \IteratorAggregate, SelfCheckingResourceInterface
         }
     }
 
-    public function getPrefix()
+    public function getPrefix(): string
     {
         return $this->prefix;
     }
@@ -60,7 +60,7 @@ class GlobResource implements \IteratorAggregate, SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'glob.'.$this->prefix.$this->pattern.(int) $this->recursive;
     }
@@ -68,7 +68,7 @@ class GlobResource implements \IteratorAggregate, SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         $hash = $this->computeHash();
 
@@ -91,7 +91,7 @@ class GlobResource implements \IteratorAggregate, SelfCheckingResourceInterface
         return ['prefix', 'pattern', 'recursive', 'hash', 'forExclusion', 'excludedPrefixes'];
     }
 
-    public function getIterator()
+    public function getIterator(): \Traversable
     {
         if (!file_exists($this->prefix) || (!$this->recursive && '' === $this->pattern)) {
             return;
@@ -171,7 +171,7 @@ class GlobResource implements \IteratorAggregate, SelfCheckingResourceInterface
         }
     }
 
-    private function computeHash()
+    private function computeHash(): string
     {
         $hash = hash_init('md5');
 
diff --git a/src/Symfony/Component/Config/Resource/ReflectionClassResource.php b/src/Symfony/Component/Config/Resource/ReflectionClassResource.php
index 14bbf7c226..a03379f0de 100644
--- a/src/Symfony/Component/Config/Resource/ReflectionClassResource.php
+++ b/src/Symfony/Component/Config/Resource/ReflectionClassResource.php
@@ -38,7 +38,7 @@ class ReflectionClassResource implements SelfCheckingResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function isFresh(int $timestamp)
+    public function isFresh(int $timestamp): bool
     {
         if (null === $this->hash) {
             $this->hash = $this->computeHash();
@@ -58,7 +58,7 @@ class ReflectionClassResource implements SelfCheckingResourceInterface
         return true;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         return 'reflection.'.$this->className;
     }
diff --git a/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php b/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php
index cd55345d77..ff765d7b2e 100644
--- a/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php
+++ b/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php
@@ -109,7 +109,7 @@ EOPHP;
         }
     }
 
-    public function provideHashedSignature()
+    public function provideHashedSignature(): iterable
     {
         yield [0, 0, "// line change\n\n"];
         yield [1, 0, '/** class docblock */'];
diff --git a/src/Symfony/Component/Console/Helper/ProcessHelper.php b/src/Symfony/Component/Console/Helper/ProcessHelper.php
index 55a3354bcf..fbd7d4baf4 100644
--- a/src/Symfony/Component/Console/Helper/ProcessHelper.php
+++ b/src/Symfony/Component/Console/Helper/ProcessHelper.php
@@ -37,7 +37,7 @@ class ProcessHelper extends Helper
      *
      * @return Process The process that ran
      */
-    public function run(OutputInterface $output, $cmd, $error = null, callable $callback = null, $verbosity = OutputInterface::VERBOSITY_VERY_VERBOSE)
+    public function run(OutputInterface $output, $cmd, $error = null, callable $callback = null, $verbosity = OutputInterface::VERBOSITY_VERY_VERBOSE): Process
     {
         if ($output instanceof ConsoleOutputInterface) {
             $output = $output->getErrorOutput();
@@ -103,7 +103,7 @@ class ProcessHelper extends Helper
      *
      * @see run()
      */
-    public function mustRun(OutputInterface $output, $cmd, $error = null, callable $callback = null)
+    public function mustRun(OutputInterface $output, $cmd, $error = null, callable $callback = null): Process
     {
         $process = $this->run($output, $cmd, $error, $callback);
 
@@ -120,10 +120,8 @@ class ProcessHelper extends Helper
      * @param OutputInterface $output   An OutputInterface interface
      * @param Process         $process  The Process
      * @param callable|null   $callback A PHP callable
-     *
-     * @return callable
      */
-    public function wrapCallback(OutputInterface $output, Process $process, callable $callback = null)
+    public function wrapCallback(OutputInterface $output, Process $process, callable $callback = null): callable
     {
         if ($output instanceof ConsoleOutputInterface) {
             $output = $output->getErrorOutput();
@@ -148,7 +146,7 @@ class ProcessHelper extends Helper
     /**
      * {@inheritdoc}
      */
-    public function getName()
+    public function getName(): string
     {
         return 'process';
     }
diff --git a/src/Symfony/Component/Debug/ErrorHandler.php b/src/Symfony/Component/Debug/ErrorHandler.php
index 2f250cba36..2d0f7a6e52 100644
--- a/src/Symfony/Component/Debug/ErrorHandler.php
+++ b/src/Symfony/Component/Debug/ErrorHandler.php
@@ -112,7 +112,7 @@ class ErrorHandler
      *
      * @return self The registered error handler
      */
-    public static function register(self $handler = null, $replace = true)
+    public static function register(self $handler = null, $replace = true): self
     {
         if (null === self::$reservedMemory) {
             self::$reservedMemory = str_repeat('x', 10240);
@@ -210,7 +210,7 @@ class ErrorHandler
      *
      * @throws \InvalidArgumentException
      */
-    public function setLoggers(array $loggers)
+    public function setLoggers(array $loggers): array
     {
         $prevLogged = $this->loggedErrors;
         $prev = $this->loggers;
@@ -261,7 +261,7 @@ class ErrorHandler
      *
      * @return callable|null The previous exception handler
      */
-    public function setExceptionHandler(callable $handler = null)
+    public function setExceptionHandler(callable $handler = null): ?callable
     {
         $prev = $this->exceptionHandler;
         $this->exceptionHandler = $handler;
@@ -277,7 +277,7 @@ class ErrorHandler
      *
      * @return int The previous value
      */
-    public function throwAt($levels, $replace = false)
+    public function throwAt($levels, $replace = false): int
     {
         $prev = $this->thrownErrors;
         $this->thrownErrors = ($levels | E_RECOVERABLE_ERROR | E_USER_ERROR) & ~E_USER_DEPRECATED & ~E_DEPRECATED;
@@ -297,7 +297,7 @@ class ErrorHandler
      *
      * @return int The previous value
      */
-    public function scopeAt($levels, $replace = false)
+    public function scopeAt($levels, $replace = false): int
     {
         $prev = $this->scopedErrors;
         $this->scopedErrors = (int) $levels;
@@ -316,7 +316,7 @@ class ErrorHandler
      *
      * @return int The previous value
      */
-    public function traceAt($levels, $replace = false)
+    public function traceAt($levels, $replace = false): int
     {
         $prev = $this->tracedErrors;
         $this->tracedErrors = (int) $levels;
@@ -335,7 +335,7 @@ class ErrorHandler
      *
      * @return int The previous value
      */
-    public function screamAt($levels, $replace = false)
+    public function screamAt($levels, $replace = false): int
     {
         $prev = $this->screamedErrors;
         $this->screamedErrors = (int) $levels;
@@ -374,7 +374,7 @@ class ErrorHandler
      * @param string $file
      * @param int    $line
      *
-     * @return bool Returns false when no handling happens so that the PHP engine can handle the error itself
+     * @return bool|void Returns false when no handling happens so that the PHP engine can handle the error itself
      *
      * @throws \ErrorException When $this->thrownErrors requests so
      *
@@ -670,7 +670,7 @@ class ErrorHandler
      *
      * @return FatalErrorHandlerInterface[] An array of FatalErrorHandlerInterface
      */
-    protected function getFatalErrorHandlers()
+    protected function getFatalErrorHandlers(): array
     {
         return [
             new UndefinedFunctionFatalErrorHandler(),
@@ -682,7 +682,7 @@ class ErrorHandler
     /**
      * Cleans the trace by removing function arguments and the frames added by the error handler and DebugClassLoader.
      */
-    private function cleanTrace($backtrace, $type, $file, $line, $throw)
+    private function cleanTrace($backtrace, $type, $file, $line, $throw): array
     {
         $lightTrace = $backtrace;
 
diff --git a/src/Symfony/Component/Debug/ExceptionHandler.php b/src/Symfony/Component/Debug/ExceptionHandler.php
index 7ae85eebb7..341e13ac8c 100644
--- a/src/Symfony/Component/Debug/ExceptionHandler.php
+++ b/src/Symfony/Component/Debug/ExceptionHandler.php
@@ -84,7 +84,7 @@ class ExceptionHandler
      *
      * @return callable|null The previous exception handler if any
      */
-    public function setHandler(callable $handler = null)
+    public function setHandler(callable $handler = null): ?callable
     {
         $old = $this->handler;
         $this->handler = $handler;
@@ -99,7 +99,7 @@ class ExceptionHandler
      *
      * @return string The previous file link format
      */
-    public function setFileLinkFormat($fileLinkFormat)
+    public function setFileLinkFormat($fileLinkFormat): string
     {
         $old = $this->fileLinkFormat;
         $this->fileLinkFormat = $fileLinkFormat;
@@ -196,7 +196,7 @@ class ExceptionHandler
      *
      * @return string The HTML content as a string
      */
-    public function getHtml($exception)
+    public function getHtml($exception): string
     {
         if (!$exception instanceof FlattenException) {
             $exception = FlattenException::create($exception);
@@ -210,7 +210,7 @@ class ExceptionHandler
      *
      * @return string The content as a string
      */
-    public function getContent(FlattenException $exception)
+    public function getContent(FlattenException $exception): string
     {
         switch ($exception->getStatusCode()) {
             case 404:
@@ -295,7 +295,7 @@ EOF;
      *
      * @return string The stylesheet as a string
      */
-    public function getStylesheet(FlattenException $exception)
+    public function getStylesheet(FlattenException $exception): string
     {
         if (!$this->debug) {
             return <<<'EOF'
@@ -355,7 +355,7 @@ EOF;
 EOF;
     }
 
-    private function decorate($content, $css)
+    private function decorate($content, $css): string
     {
         return <<<EOF
 <!DOCTYPE html>
@@ -372,14 +372,14 @@ EOF;
 EOF;
     }
 
-    private function formatClass($class)
+    private function formatClass($class): string
     {
         $parts = explode('\\', $class);
 
         return sprintf('<abbr title="%s">%s</abbr>', $class, array_pop($parts));
     }
 
-    private function formatPath($path, $line)
+    private function formatPath($path, $line): string
     {
         $file = $this->escapeHtml(preg_match('#[^/\\\\]*+$#', $path, $file) ? $file[0] : $path);
         $fmt = $this->fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');
@@ -415,10 +415,8 @@ EOF;
      * Formats an array as a string.
      *
      * @param array $args The argument array
-     *
-     * @return string
      */
-    private function formatArgs(array $args)
+    private function formatArgs(array $args): string
     {
         $result = [];
         foreach ($args as $key => $item) {
@@ -445,17 +443,17 @@ EOF;
     /**
      * HTML-encodes a string.
      */
-    private function escapeHtml($str)
+    private function escapeHtml($str): string
     {
         return htmlspecialchars($str, ENT_COMPAT | ENT_SUBSTITUTE, $this->charset);
     }
 
-    private function getSymfonyGhostAsSvg()
+    private function getSymfonyGhostAsSvg(): string
     {
         return '<svg viewBox="0 0 136 81" xmlns="http://www.w3.org/2000/svg" fill-rule="evenodd" clip-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="1.4"><path d="M92.4 20.4a23.2 23.2 0 0 1 9 1.9 23.7 23.7 0 0 1 5.2 3 24.3 24.3 0 0 1 3.4 3.4 24.8 24.8 0 0 1 5 9.4c.5 1.7.8 3.4 1 5.2v14.5h.4l.5.2a7.4 7.4 0 0 0 2.5.2l.2-.2.6-.8.8-1.3-.2-.1a5.5 5.5 0 0 1-.8-.3 5.6 5.6 0 0 1-2.3-1.8 5.7 5.7 0 0 1-.9-1.6 6.5 6.5 0 0 1-.2-2.8 7.3 7.3 0 0 1 .5-2l.3-.3.8-.9.3-.3c.2-.2.5-.3.8-.3H120.7c.2 0 .3-.1.4 0h.4l.2.1.3.2.2-.4.3-.4.1-.1 1.2-1 .3-.2.4-.1.4-.1h.3l1.5.1.4.1.8.5.1.2 1 1.1v.2H129.4l.4-.2 1.4-.5h1.1c.3 0 .7.2 1 .4.2 0 .3.2.5.3l.2.2.5.3.4.6.1.3.4 1.4.1.4v.6a7.8 7.8 0 0 1-.1.6 9.9 9.9 0 0 1-.8 2.4 7.8 7.8 0 0 1-3 3.3 6.4 6.4 0 0 1-1 .5 6.1 6.1 0 0 1-.6.2l-.7.1h-.1a23.4 23.4 0 0 1-.2 1.7 14.3 14.3 0 0 1-.6 2.1l-.8 2a9.2 9.2 0 0 1-.4.6l-.7 1a9.1 9.1 0 0 1-2.3 2.2c-.9.5-2 .6-3 .7l-1.4.1h-.5l-.4.1a15.8 15.8 0 0 1-2.8-.1v4.2a9.7 9.7 0 0 1-.7 3.5 9.6 9.6 0 0 1-1.7 2.8 9.3 9.3 0 0 1-3 2.3 9 9 0 0 1-5.4.7 9 9 0 0 1-3-1 9.4 9.4 0 0 1-2.7-2.5 10 10 0 0 1-1 1.2 9.3 9.3 0 0 1-2 1.3 9 9 0 0 1-2.4 1 9 9 0 0 1-6.5-1.1A9.4 9.4 0 0 1 85 77V77a10.9 10.9 0 0 1-.6.6 9.3 9.3 0 0 1-2.7 2 9 9 0 0 1-6 .8 9 9 0 0 1-2.4-1 9.3 9.3 0 0 1-2.3-1.7 9.6 9.6 0 0 1-1.8-2.8 9.7 9.7 0 0 1-.8-3.7v-4a18.5 18.5 0 0 1-2.9.2l-1.2-.1c-1.9-.3-3.7-1-5.1-2.1A8.2 8.2 0 0 1 58 64a10.2 10.2 0 0 1-.9-1.2 15.3 15.3 0 0 1-.7-1.3 20.8 20.8 0 0 1-1.9-6.2v-.2a6.5 6.5 0 0 1-1-.3 6.1 6.1 0 0 1-.6-.3 6.6 6.6 0 0 1-.9-.5 8.2 8.2 0 0 1-2.7-3.8 10 10 0 0 1-.3-1 10.3 10.3 0 0 1-.3-1.9V47v-.4l.1-.4.6-1.4.1-.2a2 2 0 0 1 .8-.8l.3-.2.3-.2a3.2 3.2 0 0 1 1.8-.5h.4l.3.2 1.4.6.2.2.4.3.3.4.7-.7.2-.2.4-.2.6-.2h2.1l.4.2.4.2.3.2.8 1 .2-.1h.1v-.1H63l1.1.1h.3l.8.5.3.4.7 1 .2.3.1.5a11 11 0 0 1 .2 1.5c0 .8 0 1.6-.3 2.3a6 6 0 0 1-.5 1.2 5.5 5.5 0 0 1-3.3 2.5 12.3 12.3 0 0 0 1.4 3h.1l.2.1 1 .2h1.5l.5-.2H67.8l.5-.2h.1V44v-.4a26.7 26.7 0 0 1 .3-2.3 24.7 24.7 0 0 1 5.7-12.5 24.2 24.2 0 0 1 3.5-3.3 23.7 23.7 0 0 1 4.9-3 23.2 23.2 0 0 1 5.6-1.7 23.7 23.7 0 0 1 4-.3zm-.3 2a21.2 21.2 0 0 0-8 1.7 21.6 21.6 0 0 0-4.8 2.7 22.2 22.2 0 0 0-3.2 3 22.7 22.7 0 0 0-5 9.2 23.4 23.4 0 0 0-.7 4.9v15.7l-.5.1a34.3 34.3 0 0 1-1.5.3h-.2l-.4.1h-.4l-.9.2a10 10 0 0 1-1.9 0c-.5 0-1-.2-1.5-.4a1.8 1.8 0 0 1-.3-.2 2 2 0 0 1-.3-.3 5.2 5.2 0 0 1-.1-.2 9 9 0 0 1-.6-.9 13.8 13.8 0 0 1-1-2 14.3 14.3 0 0 1-.6-2 14 14 0 0 1-.1-.8v-.2h.3a12.8 12.8 0 0 0 1.4-.2 4.4 4.4 0 0 0 .3 0 3.6 3.6 0 0 0 1.1-.7 3.4 3.4 0 0 0 1.2-1.7l.2-1.2a5.1 5.1 0 0 0 0-.8 7.2 7.2 0 0 0-.1-.8l-.7-1-1.2-.2-1 .7-.1 1.3a5 5 0 0 1 .1.4v.6a1 1 0 0 1 0 .3c-.1.3-.4.4-.7.5l-1.2.4v-.7A9.9 9.9 0 0 1 60 49l.3-.6v-.2l.1-.1v-1.6l-1-1.2h-1.5l-1 1.1v.4a5.3 5.3 0 0 0-.2.6 5.5 5.5 0 0 0 0 .5c0 .7 0 1.4.3 2 0 .4.2.8.4 1.2L57 51a9.5 9.5 0 0 1-1.1-.5h-.2a2 2 0 0 1-.4-.3c-.4-.4-.5-1-.6-1.6a5.6 5.6 0 0 1 0-.5v-.5-.5l-.6-1.5-1.4-.6-.9.3s-.2 0-.3.2a2 2 0 0 1-.1 0l-.6 1.4v.7a8.5 8.5 0 0 0 .5 2c.4 1.1 1 2.1 2 2.8a4.7 4.7 0 0 0 2.1.9h1a22.8 22.8 0 0 0 .1 1 18.1 18.1 0 0 0 .8 3.8 18.2 18.2 0 0 0 1.6 3.7l1 1.3c1 1 2.3 1.6 3.7 2a11.7 11.7 0 0 0 4.8 0h.4l.5-.2.5-.1.6-.2v6.6a8 8 0 0 0 .1 1.3 7.5 7.5 0 0 0 2.4 4.3 7.2 7.2 0 0 0 2.3 1.3 7 7 0 0 0 7-1.1 7.5 7.5 0 0 0 2-2.6A7.7 7.7 0 0 0 85 72V71a8.2 8.2 0 0 0 .2 1.3c0 .7.3 1.4.6 2a7.5 7.5 0 0 0 1.7 2.3 7.3 7.3 0 0 0 2.2 1.4 7.1 7.1 0 0 0 4.6.2 7.2 7.2 0 0 0 2.4-1.2 7.5 7.5 0 0 0 2.1-2.7 7.8 7.8 0 0 0 .7-2.4V71a9.3 9.3 0 0 0 .1.6 7.6 7.6 0 0 0 .6 2.5 7.5 7.5 0 0 0 2.4 3 7.1 7.1 0 0 0 7 .8 7.3 7.3 0 0 0 2.3-1.5 7.5 7.5 0 0 0 1.6-2.3 7.6 7.6 0 0 0 .5-2l.1-1.1v-6.7l.4.1a12.2 12.2 0 0 0 2 .5 11.1 11.1 0 0 0 2.5 0h.8l1.2-.1a9.5 9.5 0 0 0 1.4-.2l.9-.3a3.5 3.5 0 0 0 .6-.4l1.2-1.4a12.2 12.2 0 0 0 .8-1.2c0-.3.2-.5.3-.7a15.9 15.9 0 0 0 .7-2l.3-1.6v-1.3l.2-.9V54.6a15.5 15.5 0 0 0 1.8 0 4.5 4.5 0 0 0 1.4-.5 5.7 5.7 0 0 0 2.5-3.2 7.6 7.6 0 0 0 .4-1.5v-.3l-.4-1.4a5.2 5.2 0 0 1-.2-.1l-.4-.4a3.8 3.8 0 0 0-.2 0 1.4 1.4 0 0 0-.5-.2l-1.4.4-.7 1.3v.7a5.7 5.7 0 0 1-.1.8l-.7 1.4a1.9 1.9 0 0 1-.5.3h-.3a9.6 9.6 0 0 1-.8.3 8.8 8.8 0 0 1-.6 0l.2-.4.2-.5.2-.3v-.4l.1-.2V50l.1-1 .1-.6v-.6a4.8 4.8 0 0 0 0-.8v-.2l-1-1.1-1.5-.2-1.1 1-.2 1.4v.1l.2.4.2.3v.4l.1 1.1v.3l.1.5v.8a9.6 9.6 0 0 1-.8-.3l-.2-.1h-.3l-.8-.1h-.2a1.6 1.6 0 0 1-.2-.2.9.9 0 0 1-.2-.2 1 1 0 0 1-.1-.5l.2-.9v-1.2l-.9-.8h-1.2l-.8.9v.3a4.8 4.8 0 0 0-.3 2l.3.9a3.5 3.5 0 0 0 1.2 1.6l1 .5.8.2 1.4.1h.4l.2.1a12.1 12.1 0 0 1-1 2.6 13.2 13.2 0 0 1-.8 1.5 9.5 9.5 0 0 1-1 1.2l-.2.3a1.7 1.7 0 0 1-.4.3 2.4 2.4 0 0 1-.7.2h-2.5a7.8 7.8 0 0 1-.6-.2l-.7-.2h-.2a14.8 14.8 0 0 1-.6-.2 23.4 23.4 0 0 1-.4-.1l-.4-.1-.3-.1V43.9a34.6 34.6 0 0 0 0-.6 23.6 23.6 0 0 0-.4-3 22.7 22.7 0 0 0-1.5-4.7 22.6 22.6 0 0 0-4.6-6.7 21.9 21.9 0 0 0-6.9-4.7 21.2 21.2 0 0 0-8.1-1.8H92zm9.1 33.7l.3.1a1 1 0 0 1 .6.8v.4a8.4 8.4 0 0 1 0 .5 8.8 8.8 0 0 1-1.6 4.2l-1 1.3A10 10 0 0 1 95 66c-1.3.3-2.7.4-4 .3a10.4 10.4 0 0 1-2.7-.8 10 10 0 0 1-3.6-2.5 9.3 9.3 0 0 1-.8-1 9 9 0 0 1-.7-1.2 8.6 8.6 0 0 1-.8-3.4V57a1 1 0 0 1 .3-.6 1 1 0 0 1 1.3-.2 1 1 0 0 1 .4.8v.4a6.5 6.5 0 0 0 .5 2.2 7 7 0 0 0 2.1 2.8l1 .6c2.6 1.6 6 1.6 8.5 0a8 8 0 0 0 1.1-.6 7.6 7.6 0 0 0 1.2-1.2 7 7 0 0 0 1-1.7 6.5 6.5 0 0 0 .4-2.5 1 1 0 0 1 .7-1h.4zM30.7 43.7c-15.5 1-28.5-6-30.1-16.4C-1.2 15.7 11.6 4 29 1.3 46.6-1.7 62.3 5.5 64 17.1c1.6 10.4-8.7 21-23.7 25a31.2 31.2 0 0 0 0 .9v.3a19 19 0 0 0 .1 1l.1.4.1.9a4.7 4.7 0 0 0 .5 1l.7 1a9.2 9.2 0 0 0 1.2 1l1.5.8.6.8-.7.6-1.1.3a11.2 11.2 0 0 1-2.6.4 8.6 8.6 0 0 1-3-.5 8.5 8.5 0 0 1-1-.4 11.2 11.2 0 0 1-1.8-1.2 13.3 13.3 0 0 1-1-1 18 18 0 0 1-.7-.6l-.4-.4a23.4 23.4 0 0 1-1.3-1.8l-.1-.1-.3-.5V45l-.3-.6v-.7zM83.1 36c3.6 0 6.5 3.2 6.5 7.1 0 4-3 7.2-6.5 7.2S76.7 47 76.7 43 79.6 36 83 36zm18 0c3.6 0 6.5 3.2 6.5 7.1 0 4-2.9 7.2-6.4 7.2S94.7 47 94.7 43s3-7.1 6.5-7.1zm-18 6.1c2 0 3.5 1.6 3.5 3.6S85 49.2 83 49.2s-3.4-1.6-3.4-3.6S81.2 42 83 42zm17.9 0c1.9 0 3.4 1.6 3.4 3.6s-1.5 3.6-3.4 3.6c-2 0-3.5-1.6-3.5-3.6S99.1 42 101 42zM17 28c-.3 1.6-1.8 5-5.2 5.8-2.5.6-4.1-.8-4.5-2.6-.4-1.9.7-3.5 2.1-4.5A3.5 3.5 0 0 1 8 24.6c-.4-2 .8-3.7 3.2-4.2 1.9-.5 3.1.2 3.4 1.5.3 1.1-.5 2.2-1.8 2.5-.9.3-1.6 0-1.7-.6a1.4 1.4 0 0 1 0-.7s.3.2 1 0c.7-.1 1-.7.9-1.2-.2-.6-1-.8-1.8-.6-1 .2-2 1-1.7 2.6.3 1 .9 1.6 1.5 1.8l.7-.2c1-.2 1.5 0 1.6.5 0 .4-.2 1-1.2 1.2a3.3 3.3 0 0 1-1.5 0c-.9.7-1.6 1.9-1.3 3.2.3 1.3 1.3 2.2 3 1.8 2.5-.7 3.8-3.7 4.2-5-.3-.5-.6-1-.7-1.6-.1-.5.1-1 .9-1.2.4 0 .7.2.8.8a2.8 2.8 0 0 1 0 1l.7 1c.6-2 1.4-4 1.7-4 .6-.2 1.5.6 1.5.6-.8.7-1.7 2.4-2.3 4.2.8.6 1.6 1 2.1 1 .5-.1.8-.6 1-1.2-.3-2.2 1-4.3 2.3-4.6.7-.2 1.3.2 1.4.8.1.5 0 1.3-.9 1.7-.2-1-.6-1.3-1-1.3-.4.1-.7 1.4-.4 2.8.2 1 .7 1.5 1.3 1.4.8-.2 1.3-1.2 1.7-2.1-.3-2.1.9-4.2 2.2-4.5.7-.2 1.2.1 1.4 1 .4 1.4-1 2.8-2.2 3.4.3.7.7 1 1.3.9 1-.3 1.6-1.5 2-2.5l-.5-3v-.3s1.6-.3 1.8.6v.1c.2-.6.7-1.2 1.3-1.4.8-.1 1.5.6 1.7 1.6.5 2.2-.5 4.4-1.8 4.7H33a31.9 31.9 0 0 0 1 5.2c-.4.1-1.8.4-2-.4l-.5-5.6c-.5 1-1.3 2.2-2.5 2.4-1 .3-1.6-.3-2-1.1-.5 1-1.3 2.1-2.4 2.4-.8.2-1.5-.1-2-1-.3.8-.9 1.5-1.5 1.7-.7.1-1.5-.3-2.4-1-.3.8-.4 1.6-.4 2.2 0 0-.7 0-.8-.4-.1-.5 0-1.5.3-2.7a10.3 10.3 0 0 1-.7-.8zm38.2-17.8l.2.9c.5 1.9.4 4.4.8 6.4 0 .6-.4 3-1.4 3.3-.2 0-.3 0-.4-.4-.1-.7 0-1.6-.3-2.6-.2-1.1-.8-1.6-1.5-1.5-.8.2-1.3 1-1.6 2l-.1-.5c-.2-1-1.8-.6-1.8-.6a6.2 6.2 0 0 1 .4 1.3l.2 1c-.2.5-.6 1-1.2 1l-.2.1a7 7 0 0 0-.1-.8c-.3-1.1-1-2-1.6-1.8a.7.7 0 0 0-.4.3c-1.3.3-2.4 2-2.1 3.9-.2.9-.6 1.7-1 1.9-.5 0-.8-.5-1.1-1.8l-.1-1.2a4 4 0 0 0 0-1.7c0-.4-.4-.7-.8-.6-.7.2-.9 1.7-.5 3.8-.2 1-.6 2-1.3 2-.4.2-.8-.2-1-1l-.2-3c1.2-.5 2-1 1.8-1.7-.1-.5-.8-.7-.8-.7s0 .7-1 1.2l-.2-1.4c-.1-.6-.4-1-1.7-.6l.4 1 .2 1.5h-1v.8c0 .3.4.3 1 .2 0 1.3 0 2.7.2 3.6.3 1.4 1.2 2 2 1.7 1-.2 1.6-1.3 2-2.3.3 1.2 1 2 1.9 1.7.7-.2 1.2-1.1 1.6-2.2.4.8 1.1 1.1 2 1 1.2-.4 1.7-1.6 1.8-2.8h.2c.6-.2 1-.6 1.3-1 0 .8 0 1.5.2 2.1.1.5.3.7.6.6.5-.1 1-.9 1-.9a4 4 0 0 1-.3-1c-.3-1.3.3-3.6 1-3.7.2 0 .3.2.5.7v.8l.2 1.5v.7c.2.7.7 1.3 1.5 1 1.3-.2 2-2.6 2.1-3.9.3.2.6.2 1 .1-.6-2.2 0-6.1-.3-7.9-.1-.4-1-.5-1.7-.5h-.4zm-21.5 12c.4 0 .7.3 1 1.1.2 1.3-.3 2.6-.9 2.8-.2 0-.7 0-1-1.2v-.4c0-1.3.4-2 1-2.2zm-5.2 1c.3 0 .6.2.6.5.2.6-.3 1.3-1.2 2-.3-1.4.1-2.3.6-2.5zm18-.4c-.5.2-1-.4-1.2-1.2-.2-1 0-2.1.7-2.5v.5c.2.7.6 1.5 1.3 1.9 0 .7-.2 1.2-.7 1.3zm10-1.6c0 .5.4.7 1 .6.8-.2 1-1 .8-1.6 0-.5-.4-1-1-.8-.5.1-1 .9-.8 1.8zm-14.3-5.5c0-.4-.5-.7-1-.5-.8.2-1 1-.9 1.5.2.6.5 1 1 .8.5 0 1.1-1 1-1.8z" fill="#fff" fill-opacity=".6"/>'.$this->addElementToGhost().'</svg>';
     }
 
-    private function addElementToGhost()
+    private function addElementToGhost(): string
     {
         if (!isset(self::GHOST_ADDONS[\date('m-d')])) {
             return '';
diff --git a/src/Symfony/Component/DependencyInjection/Argument/BoundArgument.php b/src/Symfony/Component/DependencyInjection/Argument/BoundArgument.php
index 4a0054e20b..60059267be 100644
--- a/src/Symfony/Component/DependencyInjection/Argument/BoundArgument.php
+++ b/src/Symfony/Component/DependencyInjection/Argument/BoundArgument.php
@@ -43,7 +43,7 @@ final class BoundArgument implements ArgumentInterface
     /**
      * {@inheritdoc}
      */
-    public function getValues()
+    public function getValues(): array
     {
         return [$this->value, $this->identifier, $this->used, $this->type, $this->file];
     }
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php b/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
index a41f6905cf..424018b7ee 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
@@ -90,10 +90,8 @@ final class ServiceLocatorTagPass extends AbstractRecursivePass
      * @param ContainerBuilder $container
      * @param Reference[]      $refMap
      * @param string|null      $callerId
-     *
-     * @return Reference
      */
-    public static function register(ContainerBuilder $container, array $refMap, $callerId = null)
+    public static function register(ContainerBuilder $container, array $refMap, $callerId = null): Reference
     {
         foreach ($refMap as $id => $ref) {
             if (!$ref instanceof Reference) {
diff --git a/src/Symfony/Component/DependencyInjection/Config/ContainerParametersResource.php b/src/Symfony/Component/DependencyInjection/Config/ContainerParametersResource.php
index 605ab04151..8ffb8dcac9 100644
--- a/src/Symfony/Component/DependencyInjection/Config/ContainerParametersResource.php
+++ b/src/Symfony/Component/DependencyInjection/Config/ContainerParametersResource.php
@@ -35,7 +35,7 @@ class ContainerParametersResource implements ResourceInterface
     /**
      * {@inheritdoc}
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'container_parameters_'.md5(serialize($this->parameters));
     }
@@ -43,7 +43,7 @@ class ContainerParametersResource implements ResourceInterface
     /**
      * @return array Tracked parameters
      */
-    public function getParameters()
+    public function getParameters(): array
     {
         return $this->parameters;
     }
diff --git a/src/Symfony/Component/DependencyInjection/ContainerBuilder.php b/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
index e2638dc749..8b13b4d7ad 100644
--- a/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
+++ b/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
@@ -384,8 +384,6 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
      * @param bool|string $trackContents Whether to track contents of the given resource. If a string is passed,
      *                                   it will be used as pattern for tracking contents of the requested directory
      *
-     * @return bool
-     *
      * @final
      */
     public function fileExists(string $path, $trackContents = true): bool
diff --git a/src/Symfony/Component/DependencyInjection/LazyProxy/PhpDumper/NullDumper.php b/src/Symfony/Component/DependencyInjection/LazyProxy/PhpDumper/NullDumper.php
index 57c644ca79..ebc6a5dc2b 100644
--- a/src/Symfony/Component/DependencyInjection/LazyProxy/PhpDumper/NullDumper.php
+++ b/src/Symfony/Component/DependencyInjection/LazyProxy/PhpDumper/NullDumper.php
@@ -25,7 +25,7 @@ class NullDumper implements DumperInterface
     /**
      * {@inheritdoc}
      */
-    public function isProxyCandidate(Definition $definition)
+    public function isProxyCandidate(Definition $definition): bool
     {
         return false;
     }
@@ -33,7 +33,7 @@ class NullDumper implements DumperInterface
     /**
      * {@inheritdoc}
      */
-    public function getProxyFactoryCode(Definition $definition, $id, $factoryCode = null)
+    public function getProxyFactoryCode(Definition $definition, $id, $factoryCode = null): string
     {
         return '';
     }
@@ -41,7 +41,7 @@ class NullDumper implements DumperInterface
     /**
      * {@inheritdoc}
      */
-    public function getProxyCode(Definition $definition)
+    public function getProxyCode(Definition $definition): string
     {
         return '';
     }
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/DefaultsConfigurator.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/DefaultsConfigurator.php
index b527fd51da..cac009f769 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/DefaultsConfigurator.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/DefaultsConfigurator.php
@@ -42,7 +42,7 @@ class DefaultsConfigurator extends AbstractServiceConfigurator
      *
      * @throws InvalidArgumentException when an invalid tag name or attribute is provided
      */
-    final public function tag(string $name, array $attributes = [])
+    final public function tag(string $name, array $attributes = []): object
     {
         if ('' === $name) {
             throw new InvalidArgumentException('The tag name in "_defaults" must be a non-empty string.');
@@ -61,10 +61,8 @@ class DefaultsConfigurator extends AbstractServiceConfigurator
 
     /**
      * Defines an instanceof-conditional to be applied to following service definitions.
-     *
-     * @return InstanceofConfigurator
      */
-    final public function instanceof(string $fqcn)
+    final public function instanceof(string $fqcn): InstanceofConfigurator
     {
         return $this->parent->instanceof($fqcn);
     }
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/ParametersConfigurator.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/ParametersConfigurator.php
index bacc60f051..800ca28435 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/ParametersConfigurator.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/ParametersConfigurator.php
@@ -32,7 +32,7 @@ class ParametersConfigurator extends AbstractConfigurator
      *
      * @return $this
      */
-    final public function set(string $name, $value)
+    final public function set(string $name, $value): object
     {
         $this->container->setParameter($name, static::processValue($value, true));
 
@@ -44,7 +44,7 @@ class ParametersConfigurator extends AbstractConfigurator
      *
      * @return $this
      */
-    final public function __invoke(string $name, $value)
+    final public function __invoke(string $name, $value): object
     {
         return $this->set($name, $value);
     }
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/PrototypeConfigurator.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/PrototypeConfigurator.php
index 119f2f252e..98b1a1e726 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/PrototypeConfigurator.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/PrototypeConfigurator.php
@@ -75,7 +75,7 @@ class PrototypeConfigurator extends AbstractServiceConfigurator
      *
      * @return $this
      */
-    final public function exclude($excludes)
+    final public function exclude($excludes): object
     {
         $this->excludes = (array) $excludes;
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/ReferenceConfigurator.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/ReferenceConfigurator.php
index 590b60a54a..e0e83c4da8 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/ReferenceConfigurator.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/ReferenceConfigurator.php
@@ -32,7 +32,7 @@ class ReferenceConfigurator extends AbstractConfigurator
     /**
      * @return $this
      */
-    final public function ignoreOnInvalid()
+    final public function ignoreOnInvalid(): object
     {
         $this->invalidBehavior = ContainerInterface::IGNORE_ON_INVALID_REFERENCE;
 
@@ -42,7 +42,7 @@ class ReferenceConfigurator extends AbstractConfigurator
     /**
      * @return $this
      */
-    final public function nullOnInvalid()
+    final public function nullOnInvalid(): object
     {
         $this->invalidBehavior = ContainerInterface::NULL_ON_INVALID_REFERENCE;
 
@@ -52,14 +52,14 @@ class ReferenceConfigurator extends AbstractConfigurator
     /**
      * @return $this
      */
-    final public function ignoreOnUninitialized()
+    final public function ignoreOnUninitialized(): object
     {
         $this->invalidBehavior = ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE;
 
         return $this;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         return $this->id;
     }
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AbstractTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AbstractTrait.php
index 57ddb480fa..871cade35b 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AbstractTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AbstractTrait.php
@@ -19,7 +19,7 @@ trait AbstractTrait
      *
      * @return $this
      */
-    final public function abstract(bool $abstract = true)
+    final public function abstract(bool $abstract = true): object
     {
         $this->definition->setAbstract($abstract);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ArgumentTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ArgumentTrait.php
index 7ec8c51d47..25e9aaba2a 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ArgumentTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ArgumentTrait.php
@@ -20,7 +20,7 @@ trait ArgumentTrait
      *
      * @return $this
      */
-    final public function args(array $arguments)
+    final public function args(array $arguments): object
     {
         $this->definition->setArguments(static::processValue($arguments, true));
 
@@ -35,7 +35,7 @@ trait ArgumentTrait
      *
      * @return $this
      */
-    final public function arg($key, $value)
+    final public function arg($key, $value): object
     {
         $this->definition->setArgument($key, static::processValue($value, true));
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutoconfigureTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutoconfigureTrait.php
index a923b3fe59..62c2c7c581 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutoconfigureTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutoconfigureTrait.php
@@ -23,7 +23,7 @@ trait AutoconfigureTrait
      *
      * @throws InvalidArgumentException when a parent is already set
      */
-    final public function autoconfigure(bool $autoconfigured = true)
+    final public function autoconfigure(bool $autoconfigured = true): object
     {
         if ($autoconfigured && $this->definition instanceof ChildDefinition) {
             throw new InvalidArgumentException(sprintf('The service "%s" cannot have a "parent" and also have "autoconfigure". Try disabling autoconfiguration for the service.', $this->id));
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutowireTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutowireTrait.php
index 4c90af849a..5c372273ce 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutowireTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AutowireTrait.php
@@ -18,7 +18,7 @@ trait AutowireTrait
      *
      * @return $this
      */
-    final public function autowire(bool $autowired = true)
+    final public function autowire(bool $autowired = true): object
     {
         $this->definition->setAutowired($autowired);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/BindTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/BindTrait.php
index 621158fdee..a7f76d248c 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/BindTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/BindTrait.php
@@ -31,7 +31,7 @@ trait BindTrait
      *
      * @return $this
      */
-    final public function bind($nameOrFqcn, $valueOrRef)
+    final public function bind($nameOrFqcn, $valueOrRef): object
     {
         $valueOrRef = static::processValue($valueOrRef, true);
         if (!preg_match('/^(?:(?:array|bool|float|int|string)[ \t]*+)?\$/', $nameOrFqcn) && !$valueOrRef instanceof Reference) {
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/CallTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/CallTrait.php
index 8e6b17a19d..3f800cdc2b 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/CallTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/CallTrait.php
@@ -25,7 +25,7 @@ trait CallTrait
      *
      * @throws InvalidArgumentException on empty $method param
      */
-    final public function call($method, array $arguments = [])
+    final public function call($method, array $arguments = []): object
     {
         $this->definition->addMethodCall($method, static::processValue($arguments, true));
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ClassTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ClassTrait.php
index ef44afe6c1..18679e68ea 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ClassTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ClassTrait.php
@@ -18,7 +18,7 @@ trait ClassTrait
      *
      * @return $this
      */
-    final public function class($class)
+    final public function class($class): object
     {
         $this->definition->setClass($class);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ConfiguratorTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ConfiguratorTrait.php
index a38283b0e7..1dff67cf8d 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ConfiguratorTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ConfiguratorTrait.php
@@ -20,7 +20,7 @@ trait ConfiguratorTrait
      *
      * @return $this
      */
-    final public function configurator($configurator)
+    final public function configurator($configurator): object
     {
         $this->definition->setConfigurator(static::processValue($configurator, true));
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DecorateTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DecorateTrait.php
index 173ad15f06..2fe364a4c6 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DecorateTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DecorateTrait.php
@@ -26,7 +26,7 @@ trait DecorateTrait
      *
      * @throws InvalidArgumentException in case the decorated service id and the new decorated service id are equals
      */
-    final public function decorate($id, $renamedId = null, $priority = 0)
+    final public function decorate($id, $renamedId = null, $priority = 0): object
     {
         $this->definition->setDecoratedService($id, $renamedId, $priority);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DeprecateTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DeprecateTrait.php
index b14a6557ee..b4598a48d6 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DeprecateTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DeprecateTrait.php
@@ -24,7 +24,7 @@ trait DeprecateTrait
      *
      * @throws InvalidArgumentException when the message template is invalid
      */
-    final public function deprecate($template = null)
+    final public function deprecate($template = null): object
     {
         $this->definition->setDeprecated(true, $template);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FactoryTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FactoryTrait.php
index b83bee0f6d..feddb20833 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FactoryTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FactoryTrait.php
@@ -22,7 +22,7 @@ trait FactoryTrait
      *
      * @return $this
      */
-    final public function factory($factory)
+    final public function factory($factory): object
     {
         if (\is_string($factory) && 1 === substr_count($factory, ':')) {
             $factoryParts = explode(':', $factory);
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FileTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FileTrait.php
index 895f5304c3..f55d7582ae 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FileTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FileTrait.php
@@ -20,7 +20,7 @@ trait FileTrait
      *
      * @return $this
      */
-    final public function file($file)
+    final public function file($file): object
     {
         $this->definition->setFile($file);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/LazyTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/LazyTrait.php
index d387dfb4b0..2f5163771a 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/LazyTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/LazyTrait.php
@@ -20,7 +20,7 @@ trait LazyTrait
      *
      * @return $this
      */
-    final public function lazy($lazy = true)
+    final public function lazy($lazy = true): object
     {
         $this->definition->setLazy((bool) $lazy);
         if (\is_string($lazy)) {
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ParentTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ParentTrait.php
index 4eba03d7ee..00f2dfafd8 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ParentTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ParentTrait.php
@@ -23,7 +23,7 @@ trait ParentTrait
      *
      * @throws InvalidArgumentException when parent cannot be set
      */
-    final public function parent(string $parent)
+    final public function parent(string $parent): object
     {
         if (!$this->allowParent) {
             throw new InvalidArgumentException(sprintf('A parent cannot be defined when either "_instanceof" or "_defaults" are also defined for service prototype "%s".', $this->id));
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PropertyTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PropertyTrait.php
index 50c2ee8636..a587509f12 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PropertyTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PropertyTrait.php
@@ -18,7 +18,7 @@ trait PropertyTrait
      *
      * @return $this
      */
-    final public function property(string $name, $value)
+    final public function property(string $name, $value): object
     {
         $this->definition->setProperty($name, static::processValue($value, true));
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PublicTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PublicTrait.php
index 9886523c95..c3528b7807 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PublicTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/PublicTrait.php
@@ -16,7 +16,7 @@ trait PublicTrait
     /**
      * @return $this
      */
-    final public function public()
+    final public function public(): object
     {
         $this->definition->setPublic(true);
 
@@ -26,7 +26,7 @@ trait PublicTrait
     /**
      * @return $this
      */
-    final public function private()
+    final public function private(): object
     {
         $this->definition->setPublic(false);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ShareTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ShareTrait.php
index 1c2f97b597..4e844bb757 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ShareTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ShareTrait.php
@@ -20,7 +20,7 @@ trait ShareTrait
      *
      * @return $this
      */
-    final public function share($shared = true)
+    final public function share($shared = true): object
     {
         $this->definition->setShared($shared);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/SyntheticTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/SyntheticTrait.php
index bf124f0a40..1ba4301fdf 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/SyntheticTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/SyntheticTrait.php
@@ -19,7 +19,7 @@ trait SyntheticTrait
      *
      * @return $this
      */
-    final public function synthetic(bool $synthetic = true)
+    final public function synthetic(bool $synthetic = true): object
     {
         $this->definition->setSynthetic($synthetic);
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/TagTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/TagTrait.php
index d17339f88b..46493fcd07 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/TagTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/TagTrait.php
@@ -23,7 +23,7 @@ trait TagTrait
      *
      * @return $this
      */
-    final public function tag($name, array $attributes = [])
+    final public function tag($name, array $attributes = []): object
     {
         if (!\is_string($name) || '' === $name) {
             throw new InvalidArgumentException(sprintf('The tag name for service "%s" must be a non-empty string.', $this->id));
diff --git a/src/Symfony/Component/DependencyInjection/ReverseContainer.php b/src/Symfony/Component/DependencyInjection/ReverseContainer.php
index 076e624c2e..15e198c143 100644
--- a/src/Symfony/Component/DependencyInjection/ReverseContainer.php
+++ b/src/Symfony/Component/DependencyInjection/ReverseContainer.php
@@ -61,11 +61,9 @@ final class ReverseContainer
     }
 
     /**
-     * @return object
-     *
      * @throws ServiceNotFoundException When the service is not reversible
      */
-    public function getService(string $id)
+    public function getService(string $id): object
     {
         if ($this->serviceContainer->has($id)) {
             return $this->serviceContainer->get($id);
diff --git a/src/Symfony/Component/Dotenv/Dotenv.php b/src/Symfony/Component/Dotenv/Dotenv.php
index 07ddcb111a..51652c7050 100644
--- a/src/Symfony/Component/Dotenv/Dotenv.php
+++ b/src/Symfony/Component/Dotenv/Dotenv.php
@@ -211,7 +211,7 @@ final class Dotenv
         }
     }
 
-    private function lexVarname()
+    private function lexVarname(): string
     {
         // var name + optional export
         if (!preg_match('/(export[ \t]++)?('.self::VARNAME_REGEX.')/A', $this->data, $matches, 0, $this->cursor)) {
@@ -239,7 +239,7 @@ final class Dotenv
         return $matches[2];
     }
 
-    private function lexValue()
+    private function lexValue(): string
     {
         if (preg_match('/[ \t]*+(?:#.*)?$/Am', $this->data, $matches, 0, $this->cursor)) {
             $this->moveCursor($matches[0]);
@@ -334,7 +334,7 @@ final class Dotenv
         return $v;
     }
 
-    private function lexNestedExpression()
+    private function lexNestedExpression(): string
     {
         ++$this->cursor;
         $value = '';
@@ -467,7 +467,7 @@ final class Dotenv
         $this->lineno += substr_count($text, "\n");
     }
 
-    private function createFormatException($message)
+    private function createFormatException($message): FormatException
     {
         return new FormatException($message, new FormatExceptionContext($this->data, $this->path, $this->lineno, $this->cursor));
     }
diff --git a/src/Symfony/Component/Dotenv/Exception/FormatException.php b/src/Symfony/Component/Dotenv/Exception/FormatException.php
index f845d7bde1..adccc8c8d1 100644
--- a/src/Symfony/Component/Dotenv/Exception/FormatException.php
+++ b/src/Symfony/Component/Dotenv/Exception/FormatException.php
@@ -27,7 +27,7 @@ final class FormatException extends \LogicException implements ExceptionInterfac
         parent::__construct(sprintf("%s in \"%s\" at line %d.\n%s", $message, $context->getPath(), $context->getLineno(), $context->getDetails()), $code, $previous);
     }
 
-    public function getContext()
+    public function getContext(): FormatExceptionContext
     {
         return $this->context;
     }
diff --git a/src/Symfony/Component/Dotenv/Exception/FormatExceptionContext.php b/src/Symfony/Component/Dotenv/Exception/FormatExceptionContext.php
index c1d32d4a7e..96d902fc8f 100644
--- a/src/Symfony/Component/Dotenv/Exception/FormatExceptionContext.php
+++ b/src/Symfony/Component/Dotenv/Exception/FormatExceptionContext.php
@@ -29,17 +29,17 @@ final class FormatExceptionContext
         $this->cursor = $cursor;
     }
 
-    public function getPath()
+    public function getPath(): string
     {
         return $this->path;
     }
 
-    public function getLineno()
+    public function getLineno(): int
     {
         return $this->lineno;
     }
 
-    public function getDetails()
+    public function getDetails(): string
     {
         $before = str_replace("\n", '\n', substr($this->data, max(0, $this->cursor - 20), min(20, $this->cursor)));
         $after = str_replace("\n", '\n', substr($this->data, $this->cursor, 20));
diff --git a/src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeImmutableToDateTimeTransformer.php b/src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeImmutableToDateTimeTransformer.php
index b0737393e4..9ecf7fc949 100644
--- a/src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeImmutableToDateTimeTransformer.php
+++ b/src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeImmutableToDateTimeTransformer.php
@@ -26,11 +26,9 @@ final class DateTimeImmutableToDateTimeTransformer implements DataTransformerInt
      *
      * @param \DateTimeImmutable|null $value A DateTimeImmutable object
      *
-     * @return \DateTime|null A \DateTime object
-     *
      * @throws TransformationFailedException If the given value is not a \DateTimeImmutable
      */
-    public function transform($value)
+    public function transform($value): ?\DateTime
     {
         if (null === $value) {
             return null;
@@ -48,11 +46,9 @@ final class DateTimeImmutableToDateTimeTransformer implements DataTransformerInt
      *
      * @param \DateTime|null $value A DateTime object
      *
-     * @return \DateTimeImmutable|null A DateTimeImmutable object
-     *
      * @throws TransformationFailedException If the given value is not a \DateTime
      */
-    public function reverseTransform($value)
+    public function reverseTransform($value): ?\DateTimeImmutable
     {
         if (null === $value) {
             return null;
diff --git a/src/Symfony/Component/Form/Extension/DataCollector/FormDataCollector.php b/src/Symfony/Component/Form/Extension/DataCollector/FormDataCollector.php
index 2e6c4fbef9..815c7a094e 100644
--- a/src/Symfony/Component/Form/Extension/DataCollector/FormDataCollector.php
+++ b/src/Symfony/Component/Form/Extension/DataCollector/FormDataCollector.php
@@ -218,7 +218,7 @@ class FormDataCollector extends DataCollector implements FormDataCollectorInterf
     /**
      * {@inheritdoc}
      */
-    public function getName()
+    public function getName(): string
     {
         return 'form';
     }
@@ -226,7 +226,7 @@ class FormDataCollector extends DataCollector implements FormDataCollectorInterf
     /**
      * {@inheritdoc}
      */
-    public function getData()
+    public function getData(): array
     {
         return $this->data;
     }
@@ -250,7 +250,7 @@ class FormDataCollector extends DataCollector implements FormDataCollectorInterf
     /**
      * {@inheritdoc}
      */
-    protected function getCasters()
+    protected function getCasters(): array
     {
         return parent::getCasters() + [
             \Exception::class => function (\Exception $e, array $a, Stub $s) {
diff --git a/src/Symfony/Component/HttpClient/NativeHttpClient.php b/src/Symfony/Component/HttpClient/NativeHttpClient.php
index 55313b1ccc..c9ccb9037d 100644
--- a/src/Symfony/Component/HttpClient/NativeHttpClient.php
+++ b/src/Symfony/Component/HttpClient/NativeHttpClient.php
@@ -402,7 +402,7 @@ final class NativeHttpClient implements HttpClientInterface, LoggerAwareInterfac
         };
     }
 
-    private static function configureHeadersAndProxy($context, string $host, array $requestHeaders, ?array $proxy, array $noProxy)
+    private static function configureHeadersAndProxy($context, string $host, array $requestHeaders, ?array $proxy, array $noProxy): bool
     {
         if (null === $proxy) {
             return stream_context_set_option($context, 'http', 'header', $requestHeaders);
diff --git a/src/Symfony/Component/HttpFoundation/Response.php b/src/Symfony/Component/HttpFoundation/Response.php
index fafc2364bc..4ce97e0908 100644
--- a/src/Symfony/Component/HttpFoundation/Response.php
+++ b/src/Symfony/Component/HttpFoundation/Response.php
@@ -418,7 +418,7 @@ class Response
      *
      * @final
      */
-    public function setProtocolVersion(string $version)
+    public function setProtocolVersion(string $version): object
     {
         $this->version = $version;
 
@@ -447,7 +447,7 @@ class Response
      *
      * @final
      */
-    public function setStatusCode(int $code, $text = null)
+    public function setStatusCode(int $code, $text = null): object
     {
         $this->statusCode = $code;
         if ($this->isInvalid()) {
@@ -488,7 +488,7 @@ class Response
      *
      * @final
      */
-    public function setCharset(string $charset)
+    public function setCharset(string $charset): object
     {
         $this->charset = $charset;
 
@@ -569,7 +569,7 @@ class Response
      *
      * @final
      */
-    public function setPrivate()
+    public function setPrivate(): object
     {
         $this->headers->removeCacheControlDirective('public');
         $this->headers->addCacheControlDirective('private');
@@ -586,7 +586,7 @@ class Response
      *
      * @final
      */
-    public function setPublic()
+    public function setPublic(): object
     {
         $this->headers->addCacheControlDirective('public');
         $this->headers->removeCacheControlDirective('private');
@@ -601,7 +601,7 @@ class Response
      *
      * @final
      */
-    public function setImmutable(bool $immutable = true)
+    public function setImmutable(bool $immutable = true): object
     {
         if ($immutable) {
             $this->headers->addCacheControlDirective('immutable');
@@ -656,7 +656,7 @@ class Response
      *
      * @final
      */
-    public function setDate(\DateTimeInterface $date)
+    public function setDate(\DateTimeInterface $date): object
     {
         if ($date instanceof \DateTime) {
             $date = \DateTimeImmutable::createFromMutable($date);
@@ -721,7 +721,7 @@ class Response
      *
      * @final
      */
-    public function setExpires(\DateTimeInterface $date = null)
+    public function setExpires(\DateTimeInterface $date = null): object
     {
         if (null === $date) {
             $this->headers->remove('Expires');
@@ -774,7 +774,7 @@ class Response
      *
      * @final
      */
-    public function setMaxAge(int $value)
+    public function setMaxAge(int $value): object
     {
         $this->headers->addCacheControlDirective('max-age', $value);
 
@@ -790,7 +790,7 @@ class Response
      *
      * @final
      */
-    public function setSharedMaxAge(int $value)
+    public function setSharedMaxAge(int $value): object
     {
         $this->setPublic();
         $this->headers->addCacheControlDirective('s-maxage', $value);
@@ -824,7 +824,7 @@ class Response
      *
      * @final
      */
-    public function setTtl(int $seconds)
+    public function setTtl(int $seconds): object
     {
         $this->setSharedMaxAge($this->getAge() + $seconds);
 
@@ -840,7 +840,7 @@ class Response
      *
      * @final
      */
-    public function setClientTtl(int $seconds)
+    public function setClientTtl(int $seconds): object
     {
         $this->setMaxAge($this->getAge() + $seconds);
 
@@ -868,7 +868,7 @@ class Response
      *
      * @final
      */
-    public function setLastModified(\DateTimeInterface $date = null)
+    public function setLastModified(\DateTimeInterface $date = null): object
     {
         if (null === $date) {
             $this->headers->remove('Last-Modified');
@@ -906,7 +906,7 @@ class Response
      *
      * @final
      */
-    public function setEtag(string $etag = null, bool $weak = false)
+    public function setEtag(string $etag = null, bool $weak = false): object
     {
         if (null === $etag) {
             $this->headers->remove('Etag');
@@ -932,7 +932,7 @@ class Response
      *
      * @final
      */
-    public function setCache(array $options)
+    public function setCache(array $options): object
     {
         if ($diff = array_diff(array_keys($options), ['etag', 'last_modified', 'max_age', 's_maxage', 'private', 'public', 'immutable'])) {
             throw new \InvalidArgumentException(sprintf('Response does not support the following options: "%s".', implode('", "', $diff)));
@@ -989,7 +989,7 @@ class Response
      *
      * @final
      */
-    public function setNotModified()
+    public function setNotModified(): object
     {
         $this->setStatusCode(304);
         $this->setContent(null);
@@ -1041,7 +1041,7 @@ class Response
      *
      * @final
      */
-    public function setVary($headers, bool $replace = true)
+    public function setVary($headers, bool $replace = true): object
     {
         $this->headers->set('Vary', $headers, $replace);
 
diff --git a/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php b/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php
index 3504bdfe7b..28b7a05ccc 100644
--- a/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php
+++ b/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php
@@ -29,20 +29,14 @@ final class SessionBagProxy implements SessionBagInterface
         $this->usageIndex = &$usageIndex;
     }
 
-    /**
-     * @return SessionBagInterface
-     */
-    public function getBag()
+    public function getBag(): SessionBagInterface
     {
         ++$this->usageIndex;
 
         return $this->bag;
     }
 
-    /**
-     * @return bool
-     */
-    public function isEmpty()
+    public function isEmpty(): bool
     {
         if (!isset($this->data[$this->bag->getStorageKey()])) {
             return true;
@@ -55,7 +49,7 @@ final class SessionBagProxy implements SessionBagInterface
     /**
      * {@inheritdoc}
      */
-    public function getName()
+    public function getName(): string
     {
         return $this->bag->getName();
     }
@@ -74,7 +68,7 @@ final class SessionBagProxy implements SessionBagInterface
     /**
      * {@inheritdoc}
      */
-    public function getStorageKey()
+    public function getStorageKey(): string
     {
         return $this->bag->getStorageKey();
     }
diff --git a/src/Symfony/Component/HttpKernel/Bundle/Bundle.php b/src/Symfony/Component/HttpKernel/Bundle/Bundle.php
index 26dea9b205..68699697d6 100644
--- a/src/Symfony/Component/HttpKernel/Bundle/Bundle.php
+++ b/src/Symfony/Component/HttpKernel/Bundle/Bundle.php
@@ -119,10 +119,8 @@ abstract class Bundle implements BundleInterface
 
     /**
      * Returns the bundle name (the class short name).
-     *
-     * @return string The Bundle name
      */
-    final public function getName()
+    final public function getName(): string
     {
         if (null === $this->name) {
             $this->parseClassName();
diff --git a/src/Symfony/Component/HttpKernel/CacheWarmer/CacheWarmerAggregate.php b/src/Symfony/Component/HttpKernel/CacheWarmer/CacheWarmerAggregate.php
index dd527708be..4a473021cf 100644
--- a/src/Symfony/Component/HttpKernel/CacheWarmer/CacheWarmerAggregate.php
+++ b/src/Symfony/Component/HttpKernel/CacheWarmer/CacheWarmerAggregate.php
@@ -114,7 +114,7 @@ class CacheWarmerAggregate implements CacheWarmerInterface
      *
      * @return bool always false
      */
-    public function isOptional()
+    public function isOptional(): bool
     {
         return false;
     }
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver.php
index 86ceab2f26..08bc941127 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver.php
@@ -43,7 +43,7 @@ final class ArgumentResolver implements ArgumentResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function getArguments(Request $request, $controller)
+    public function getArguments(Request $request, $controller): array
     {
         $arguments = [];
 
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/DefaultValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/DefaultValueResolver.php
index e58fd3ab2b..32a0e071d6 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/DefaultValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/DefaultValueResolver.php
@@ -25,7 +25,7 @@ final class DefaultValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         return $argument->hasDefaultValue() || (null !== $argument->getType() && $argument->isNullable() && !$argument->isVariadic());
     }
@@ -33,7 +33,7 @@ final class DefaultValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         yield $argument->hasDefaultValue() ? $argument->getDefaultValue() : null;
     }
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/NotTaggedControllerValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/NotTaggedControllerValueResolver.php
index 19e324dc24..b34e11b846 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/NotTaggedControllerValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/NotTaggedControllerValueResolver.php
@@ -34,7 +34,7 @@ final class NotTaggedControllerValueResolver implements ArgumentValueResolverInt
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         $controller = $request->attributes->get('_controller');
 
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestAttributeValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestAttributeValueResolver.php
index 05be372d84..c62d327b65 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestAttributeValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestAttributeValueResolver.php
@@ -25,7 +25,7 @@ final class RequestAttributeValueResolver implements ArgumentValueResolverInterf
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         return !$argument->isVariadic() && $request->attributes->has($argument->getName());
     }
@@ -33,7 +33,7 @@ final class RequestAttributeValueResolver implements ArgumentValueResolverInterf
     /**
      * {@inheritdoc}
      */
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         yield $request->attributes->get($argument->getName());
     }
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestValueResolver.php
index 2a5060a612..75cbd97edb 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/RequestValueResolver.php
@@ -25,7 +25,7 @@ final class RequestValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         return Request::class === $argument->getType() || is_subclass_of($argument->getType(), Request::class);
     }
@@ -33,7 +33,7 @@ final class RequestValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         yield $request;
     }
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/ServiceValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/ServiceValueResolver.php
index e7df546b66..4ffb8c99eb 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/ServiceValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/ServiceValueResolver.php
@@ -34,7 +34,7 @@ final class ServiceValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         $controller = $request->attributes->get('_controller');
 
@@ -58,7 +58,7 @@ final class ServiceValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         if (\is_array($controller = $request->attributes->get('_controller'))) {
             $controller = $controller[0].'::'.$controller[1];
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/SessionValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/SessionValueResolver.php
index 276d65461c..a1e6b43159 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/SessionValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/SessionValueResolver.php
@@ -26,7 +26,7 @@ final class SessionValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         if (!$request->hasSession()) {
             return false;
@@ -43,7 +43,7 @@ final class SessionValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         yield $request->getSession();
     }
diff --git a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/VariadicValueResolver.php b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/VariadicValueResolver.php
index 7ee2d7af5c..1673a490cf 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/VariadicValueResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ArgumentResolver/VariadicValueResolver.php
@@ -25,7 +25,7 @@ final class VariadicValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         return $argument->isVariadic() && $request->attributes->has($argument->getName());
     }
@@ -33,7 +33,7 @@ final class VariadicValueResolver implements ArgumentValueResolverInterface
     /**
      * {@inheritdoc}
      */
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         $values = $request->attributes->get($argument->getName());
 
diff --git a/src/Symfony/Component/HttpKernel/ControllerMetadata/ArgumentMetadataFactory.php b/src/Symfony/Component/HttpKernel/ControllerMetadata/ArgumentMetadataFactory.php
index 8ee9b0b938..1d6c5ccf53 100644
--- a/src/Symfony/Component/HttpKernel/ControllerMetadata/ArgumentMetadataFactory.php
+++ b/src/Symfony/Component/HttpKernel/ControllerMetadata/ArgumentMetadataFactory.php
@@ -21,7 +21,7 @@ final class ArgumentMetadataFactory implements ArgumentMetadataFactoryInterface
     /**
      * {@inheritdoc}
      */
-    public function createArgumentMetadata($controller)
+    public function createArgumentMetadata($controller): array
     {
         $arguments = [];
 
@@ -45,7 +45,7 @@ final class ArgumentMetadataFactory implements ArgumentMetadataFactoryInterface
      *
      * @param \ReflectionParameter $parameter
      *
-     * @return string|null
+     * @return string|null|void
      */
     private function getType(\ReflectionParameter $parameter, \ReflectionFunctionAbstract $function)
     {
diff --git a/src/Symfony/Component/HttpKernel/DataCollector/DumpDataCollector.php b/src/Symfony/Component/HttpKernel/DataCollector/DumpDataCollector.php
index b154e50ae2..a6b38099aa 100644
--- a/src/Symfony/Component/HttpKernel/DataCollector/DumpDataCollector.php
+++ b/src/Symfony/Component/HttpKernel/DataCollector/DumpDataCollector.php
@@ -148,7 +148,7 @@ class DumpDataCollector extends DataCollector implements DataDumperInterface
     /**
      * @internal
      */
-    public function __sleep()
+    public function __sleep(): array
     {
         if (!$this->dataCount) {
             $this->data = [];
@@ -180,12 +180,12 @@ class DumpDataCollector extends DataCollector implements DataDumperInterface
         self::__construct($this->stopwatch, $fileLinkFormat, $charset);
     }
 
-    public function getDumpsCount()
+    public function getDumpsCount(): int
     {
         return $this->dataCount;
     }
 
-    public function getDumps($format, $maxDepthLimit = -1, $maxItemsPerDepth = -1)
+    public function getDumps($format, $maxDepthLimit = -1, $maxItemsPerDepth = -1): array
     {
         $data = fopen('php://memory', 'r+b');
 
@@ -212,7 +212,7 @@ class DumpDataCollector extends DataCollector implements DataDumperInterface
         return $dumps;
     }
 
-    public function getName()
+    public function getName(): string
     {
         return 'dump';
     }
diff --git a/src/Symfony/Component/HttpKernel/Debug/FileLinkFormatter.php b/src/Symfony/Component/HttpKernel/Debug/FileLinkFormatter.php
index 4b848692c0..e6d31516d7 100644
--- a/src/Symfony/Component/HttpKernel/Debug/FileLinkFormatter.php
+++ b/src/Symfony/Component/HttpKernel/Debug/FileLinkFormatter.php
@@ -76,7 +76,7 @@ class FileLinkFormatter
     /**
      * @internal
      */
-    public static function generateUrlFormat(UrlGeneratorInterface $router, $routeName, $queryString)
+    public static function generateUrlFormat(UrlGeneratorInterface $router, $routeName, $queryString): ?string
     {
         try {
             return $router->generate($routeName).$queryString;
diff --git a/src/Symfony/Component/HttpKernel/EventListener/AddRequestFormatsListener.php b/src/Symfony/Component/HttpKernel/EventListener/AddRequestFormatsListener.php
index f3b868bdb4..9e896adb31 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/AddRequestFormatsListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/AddRequestFormatsListener.php
@@ -45,7 +45,7 @@ class AddRequestFormatsListener implements EventSubscriberInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [KernelEvents::REQUEST => ['onKernelRequest', 100]];
     }
diff --git a/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php b/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php
index b091d63a67..dc454958f7 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php
@@ -167,7 +167,7 @@ class DebugHandlersListener implements EventSubscriberInterface
         (new ExceptionListener($controller, $this->logger, $debug))->onKernelException($event);
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         $events = [KernelEvents::REQUEST => ['configure', 2048]];
 
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php b/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
index 55ab67a025..3ea2838ac7 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
@@ -94,7 +94,7 @@ class ExceptionListener implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::EXCEPTION => [
@@ -126,10 +126,8 @@ class ExceptionListener implements EventSubscriberInterface
      *
      * @param \Exception $exception The thrown exception
      * @param Request    $request   The original request
-     *
-     * @return Request The cloned request
      */
-    protected function duplicateRequest(\Exception $exception, Request $request)
+    protected function duplicateRequest(\Exception $exception, Request $request): Request
     {
         $attributes = [
             '_controller' => $this->controller,
diff --git a/src/Symfony/Component/HttpKernel/EventListener/FragmentListener.php b/src/Symfony/Component/HttpKernel/EventListener/FragmentListener.php
index c6247161c7..17a3b94fb7 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/FragmentListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/FragmentListener.php
@@ -92,7 +92,7 @@ class FragmentListener implements EventSubscriberInterface
         throw new AccessDeniedHttpException();
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::REQUEST => [['onKernelRequest', 48]],
diff --git a/src/Symfony/Component/HttpKernel/EventListener/LocaleListener.php b/src/Symfony/Component/HttpKernel/EventListener/LocaleListener.php
index 5519bf285a..3bad8f7b02 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/LocaleListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/LocaleListener.php
@@ -79,7 +79,7 @@ class LocaleListener implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::REQUEST => [
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ProfilerListener.php b/src/Symfony/Component/HttpKernel/EventListener/ProfilerListener.php
index c5846f4ea3..4ad8f1741e 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ProfilerListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ProfilerListener.php
@@ -119,7 +119,7 @@ class ProfilerListener implements EventSubscriberInterface
         $this->parents = new \SplObjectStorage();
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::RESPONSE => ['onKernelResponse', -100],
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ResponseListener.php b/src/Symfony/Component/HttpKernel/EventListener/ResponseListener.php
index e31fb4b2c5..d8292aec43 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ResponseListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ResponseListener.php
@@ -49,7 +49,7 @@ class ResponseListener implements EventSubscriberInterface
         $response->prepare($event->getRequest());
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::RESPONSE => 'onKernelResponse',
diff --git a/src/Symfony/Component/HttpKernel/EventListener/RouterListener.php b/src/Symfony/Component/HttpKernel/EventListener/RouterListener.php
index 563f71fac6..597ca3a53e 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/RouterListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/RouterListener.php
@@ -157,7 +157,7 @@ class RouterListener implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::REQUEST => [['onKernelRequest', 32]],
@@ -166,7 +166,7 @@ class RouterListener implements EventSubscriberInterface
         ];
     }
 
-    private function createWelcomeResponse()
+    private function createWelcomeResponse(): Response
     {
         $version = Kernel::VERSION;
         $baseDir = realpath($this->projectDir).\DIRECTORY_SEPARATOR;
diff --git a/src/Symfony/Component/HttpKernel/EventListener/StreamedResponseListener.php b/src/Symfony/Component/HttpKernel/EventListener/StreamedResponseListener.php
index 18ed56a57a..730ee5453f 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/StreamedResponseListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/StreamedResponseListener.php
@@ -42,7 +42,7 @@ class StreamedResponseListener implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::RESPONSE => ['onKernelResponse', -1024],
diff --git a/src/Symfony/Component/HttpKernel/EventListener/SurrogateListener.php b/src/Symfony/Component/HttpKernel/EventListener/SurrogateListener.php
index 551754c59c..2ef4af7aa3 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/SurrogateListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/SurrogateListener.php
@@ -58,7 +58,7 @@ class SurrogateListener implements EventSubscriberInterface
         $surrogate->addSurrogateControl($event->getResponse());
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::RESPONSE => 'onKernelResponse',
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ValidateRequestListener.php b/src/Symfony/Component/HttpKernel/EventListener/ValidateRequestListener.php
index 6158c01efb..1f0c79822d 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ValidateRequestListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ValidateRequestListener.php
@@ -44,7 +44,7 @@ class ValidateRequestListener implements EventSubscriberInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             KernelEvents::REQUEST => [
diff --git a/src/Symfony/Component/Intl/Countries.php b/src/Symfony/Component/Intl/Countries.php
index 81e17a5d59..5f2642aa08 100644
--- a/src/Symfony/Component/Intl/Countries.php
+++ b/src/Symfony/Component/Intl/Countries.php
@@ -60,7 +60,7 @@ final class Countries extends ResourceBundle
     /**
      * @return string[]
      */
-    public static function getNames($displayLocale = null)
+    public static function getNames($displayLocale = null): array
     {
         return self::asort(self::readEntry(['Names'], $displayLocale), $displayLocale);
     }
diff --git a/src/Symfony/Component/Intl/Intl.php b/src/Symfony/Component/Intl/Intl.php
index e4c73273b3..52aba34949 100644
--- a/src/Symfony/Component/Intl/Intl.php
+++ b/src/Symfony/Component/Intl/Intl.php
@@ -69,7 +69,7 @@ final class Intl
      *
      * @return bool Returns true if the intl extension is installed, false otherwise
      */
-    public static function isExtensionLoaded()
+    public static function isExtensionLoaded(): bool
     {
         return class_exists('\ResourceBundle');
     }
@@ -79,7 +79,7 @@ final class Intl
      *
      * @return string|null The ICU version or NULL if it could not be determined
      */
-    public static function getIcuVersion()
+    public static function getIcuVersion(): ?string
     {
         if (false === self::$icuVersion) {
             if (!self::isExtensionLoaded()) {
@@ -109,7 +109,7 @@ final class Intl
      *
      * @return string The version of the installed ICU data
      */
-    public static function getIcuDataVersion()
+    public static function getIcuDataVersion(): string
     {
         if (false === self::$icuDataVersion) {
             self::$icuDataVersion = trim(file_get_contents(self::getDataDirectory().'/version.txt'));
@@ -123,7 +123,7 @@ final class Intl
      *
      * @return string The ICU version of the stub classes
      */
-    public static function getIcuStubVersion()
+    public static function getIcuStubVersion(): string
     {
         return '64.2';
     }
@@ -133,7 +133,7 @@ final class Intl
      *
      * @return string The absolute path to the data directory
      */
-    public static function getDataDirectory()
+    public static function getDataDirectory(): string
     {
         return __DIR__.'/Resources/data';
     }
diff --git a/src/Symfony/Component/Intl/Locales.php b/src/Symfony/Component/Intl/Locales.php
index 1f434ee267..aee16beb16 100644
--- a/src/Symfony/Component/Intl/Locales.php
+++ b/src/Symfony/Component/Intl/Locales.php
@@ -67,7 +67,7 @@ final class Locales extends ResourceBundle
     /**
      * @return string[]
      */
-    public static function getNames($displayLocale = null)
+    public static function getNames($displayLocale = null): array
     {
         return self::asort(self::readEntry(['Names'], $displayLocale), $displayLocale);
     }
diff --git a/src/Symfony/Component/Intl/Scripts.php b/src/Symfony/Component/Intl/Scripts.php
index bf26969c06..943ef8b469 100644
--- a/src/Symfony/Component/Intl/Scripts.php
+++ b/src/Symfony/Component/Intl/Scripts.php
@@ -51,7 +51,7 @@ final class Scripts extends ResourceBundle
     /**
      * @return string[]
      */
-    public static function getNames($displayLocale = null)
+    public static function getNames($displayLocale = null): array
     {
         return self::asort(self::readEntry(['Names'], $displayLocale), $displayLocale);
     }
diff --git a/src/Symfony/Component/Intl/Util/GitRepository.php b/src/Symfony/Component/Intl/Util/GitRepository.php
index d6574601b4..2c22ca7ba2 100644
--- a/src/Symfony/Component/Intl/Util/GitRepository.php
+++ b/src/Symfony/Component/Intl/Util/GitRepository.php
@@ -44,7 +44,7 @@ final class GitRepository
         return new self(realpath($targetDir));
     }
 
-    public function getPath()
+    public function getPath(): string
     {
         return $this->path;
     }
@@ -64,7 +64,7 @@ final class GitRepository
         return $this->getLastLine($this->execInPath('git log -1 --format="%an"'));
     }
 
-    public function getLastAuthoredDate()
+    public function getLastAuthoredDate(): \DateTime
     {
         return new \DateTime($this->getLastLine($this->execInPath('git log -1 --format="%ai"')));
     }
diff --git a/src/Symfony/Component/Ldap/Adapter/ExtLdap/ConnectionOptions.php b/src/Symfony/Component/Ldap/Adapter/ExtLdap/ConnectionOptions.php
index 304ba7801b..7a4225fb42 100644
--- a/src/Symfony/Component/Ldap/Adapter/ExtLdap/ConnectionOptions.php
+++ b/src/Symfony/Component/Ldap/Adapter/ExtLdap/ConnectionOptions.php
@@ -45,7 +45,7 @@ final class ConnectionOptions
     const X_SASL_AUTHCID = 0x6102;
     const X_SASL_AUTHZID = 0x6103;
 
-    public static function getOptionName($name)
+    public static function getOptionName($name): string
     {
         return sprintf('%s::%s', self::class, strtoupper($name));
     }
@@ -56,11 +56,9 @@ final class ConnectionOptions
      *
      * @param string $name
      *
-     * @return int
-     *
      * @throws LdapException
      */
-    public static function getOption($name)
+    public static function getOption($name): int
     {
         // Convert
         $constantName = self::getOptionName($name);
@@ -72,7 +70,7 @@ final class ConnectionOptions
         return \constant($constantName);
     }
 
-    public static function isOption($name)
+    public static function isOption($name): bool
     {
         return \defined(self::getOptionName($name));
     }
diff --git a/src/Symfony/Component/Ldap/Ldap.php b/src/Symfony/Component/Ldap/Ldap.php
index 615dbcfda3..16ba165c84 100644
--- a/src/Symfony/Component/Ldap/Ldap.php
+++ b/src/Symfony/Component/Ldap/Ldap.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\Ldap;
 
 use Symfony\Component\Ldap\Adapter\AdapterInterface;
+use Symfony\Component\Ldap\Adapter\EntryManagerInterface;
+use Symfony\Component\Ldap\Adapter\QueryInterface;
 use Symfony\Component\Ldap\Exception\DriverNotFoundException;
 
 /**
@@ -41,7 +43,7 @@ final class Ldap implements LdapInterface
     /**
      * {@inheritdoc}
      */
-    public function query($dn, $query, array $options = [])
+    public function query($dn, $query, array $options = []): ?QueryInterface
     {
         return $this->adapter->createQuery($dn, $query, $options);
     }
@@ -49,7 +51,7 @@ final class Ldap implements LdapInterface
     /**
      * {@inheritdoc}
      */
-    public function getEntryManager()
+    public function getEntryManager(): ?EntryManagerInterface
     {
         return $this->adapter->getEntryManager();
     }
@@ -57,7 +59,7 @@ final class Ldap implements LdapInterface
     /**
      * {@inheritdoc}
      */
-    public function escape($subject, $ignore = '', $flags = 0)
+    public function escape($subject, $ignore = '', $flags = 0): ?string
     {
         return $this->adapter->escape($subject, $ignore, $flags);
     }
diff --git a/src/Symfony/Component/Lock/Key.php b/src/Symfony/Component/Lock/Key.php
index e20fbd9c80..c53892ab6b 100644
--- a/src/Symfony/Component/Lock/Key.php
+++ b/src/Symfony/Component/Lock/Key.php
@@ -27,7 +27,7 @@ final class Key
         $this->resource = $resource;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         return $this->resource;
     }
@@ -74,15 +74,12 @@ final class Key
      *
      * @return float|null Remaining lifetime in seconds. Null when the key won't expire.
      */
-    public function getRemainingLifetime()
+    public function getRemainingLifetime(): ?float
     {
         return null === $this->expiringTime ? null : $this->expiringTime - microtime(true);
     }
 
-    /**
-     * @return bool
-     */
-    public function isExpired()
+    public function isExpired(): bool
     {
         return null !== $this->expiringTime && $this->expiringTime <= microtime(true);
     }
diff --git a/src/Symfony/Component/Lock/Lock.php b/src/Symfony/Component/Lock/Lock.php
index 97117a8204..af9f2af458 100644
--- a/src/Symfony/Component/Lock/Lock.php
+++ b/src/Symfony/Component/Lock/Lock.php
@@ -66,7 +66,7 @@ final class Lock implements LockInterface, LoggerAwareInterface
     /**
      * {@inheritdoc}
      */
-    public function acquire($blocking = false)
+    public function acquire($blocking = false): ?bool
     {
         try {
             if ($blocking) {
@@ -169,7 +169,7 @@ final class Lock implements LockInterface, LoggerAwareInterface
     /**
      * {@inheritdoc}
      */
-    public function isExpired()
+    public function isExpired(): bool
     {
         return $this->key->isExpired();
     }
diff --git a/src/Symfony/Component/Messenger/Envelope.php b/src/Symfony/Component/Messenger/Envelope.php
index be012fba94..162e8b8033 100644
--- a/src/Symfony/Component/Messenger/Envelope.php
+++ b/src/Symfony/Component/Messenger/Envelope.php
@@ -116,7 +116,7 @@ final class Envelope
     /**
      * @return object The original message contained in the envelope
      */
-    public function getMessage()
+    public function getMessage(): object
     {
         return $this->message;
     }
diff --git a/src/Symfony/Component/Messenger/Handler/HandlerDescriptor.php b/src/Symfony/Component/Messenger/Handler/HandlerDescriptor.php
index e02d95ed0f..3841e2220a 100644
--- a/src/Symfony/Component/Messenger/Handler/HandlerDescriptor.php
+++ b/src/Symfony/Component/Messenger/Handler/HandlerDescriptor.php
@@ -51,7 +51,7 @@ final class HandlerDescriptor
         return $this->options[$option] ?? null;
     }
 
-    private function callableName(callable $handler)
+    private function callableName(callable $handler): string
     {
         if (\is_array($handler)) {
             if (\is_object($handler[0])) {
diff --git a/src/Symfony/Component/Messenger/Transport/AmqpExt/Connection.php b/src/Symfony/Component/Messenger/Transport/AmqpExt/Connection.php
index 51ef98dd31..44b2c26192 100644
--- a/src/Symfony/Component/Messenger/Transport/AmqpExt/Connection.php
+++ b/src/Symfony/Component/Messenger/Transport/AmqpExt/Connection.php
@@ -270,7 +270,7 @@ class Connection
      * which is the original exchange, resulting on it being put back into
      * the original queue.
      */
-    private function createDelayQueue(int $delay, ?string $routingKey)
+    private function createDelayQueue(int $delay, ?string $routingKey): \AMQPQueue
     {
         $queue = $this->amqpFactory->createQueue($this->channel());
         $queue->setName(str_replace(
diff --git a/src/Symfony/Component/Messenger/Transport/Doctrine/Connection.php b/src/Symfony/Component/Messenger/Transport/Doctrine/Connection.php
index bd528b5b43..1dcb8dce72 100644
--- a/src/Symfony/Component/Messenger/Transport/Doctrine/Connection.php
+++ b/src/Symfony/Component/Messenger/Transport/Doctrine/Connection.php
@@ -65,7 +65,7 @@ class Connection
         return $this->configuration;
     }
 
-    public static function buildConfiguration($dsn, array $options = [])
+    public static function buildConfiguration($dsn, array $options = []): array
     {
         if (false === $components = parse_url($dsn)) {
             throw new InvalidArgumentException(sprintf('The given Doctrine Messenger DSN "%s" is invalid.', $dsn));
@@ -328,7 +328,7 @@ class Connection
         return $schema;
     }
 
-    public static function formatDateTime(\DateTimeInterface $dateTime)
+    public static function formatDateTime(\DateTimeInterface $dateTime): string
     {
         return $dateTime->format('Y-m-d\TH:i:s');
     }
diff --git a/src/Symfony/Component/Mime/Header/DateHeader.php b/src/Symfony/Component/Mime/Header/DateHeader.php
index 1e1a979569..b6964406d3 100644
--- a/src/Symfony/Component/Mime/Header/DateHeader.php
+++ b/src/Symfony/Component/Mime/Header/DateHeader.php
@@ -37,10 +37,7 @@ final class DateHeader extends AbstractHeader
         $this->setDateTime($body);
     }
 
-    /**
-     * @return \DateTimeImmutable
-     */
-    public function getBody()
+    public function getBody(): \DateTimeImmutable
     {
         return $this->getDateTime();
     }
diff --git a/src/Symfony/Component/Mime/Header/Headers.php b/src/Symfony/Component/Mime/Header/Headers.php
index c0e45e0d0a..94c5ac818e 100644
--- a/src/Symfony/Component/Mime/Header/Headers.php
+++ b/src/Symfony/Component/Mime/Header/Headers.php
@@ -66,7 +66,7 @@ final class Headers
      *
      * @return $this
      */
-    public function addMailboxListHeader(string $name, array $addresses)
+    public function addMailboxListHeader(string $name, array $addresses): object
     {
         return $this->add(new MailboxListHeader($name, Address::createArray($addresses)));
     }
@@ -76,7 +76,7 @@ final class Headers
      *
      * @return $this
      */
-    public function addMailboxHeader(string $name, $address)
+    public function addMailboxHeader(string $name, $address): object
     {
         return $this->add(new MailboxHeader($name, Address::create($address)));
     }
@@ -86,7 +86,7 @@ final class Headers
      *
      * @return $this
      */
-    public function addIdHeader(string $name, $ids)
+    public function addIdHeader(string $name, $ids): object
     {
         return $this->add(new IdentificationHeader($name, $ids));
     }
@@ -96,7 +96,7 @@ final class Headers
      *
      * @return $this
      */
-    public function addPathHeader(string $name, $path)
+    public function addPathHeader(string $name, $path): object
     {
         return $this->add(new PathHeader($name, $path instanceof Address ? $path : new Address($path)));
     }
@@ -104,7 +104,7 @@ final class Headers
     /**
      * @return $this
      */
-    public function addDateHeader(string $name, \DateTimeInterface $dateTime)
+    public function addDateHeader(string $name, \DateTimeInterface $dateTime): object
     {
         return $this->add(new DateHeader($name, $dateTime));
     }
@@ -112,7 +112,7 @@ final class Headers
     /**
      * @return $this
      */
-    public function addTextHeader(string $name, string $value)
+    public function addTextHeader(string $name, string $value): object
     {
         return $this->add(new UnstructuredHeader($name, $value));
     }
@@ -120,7 +120,7 @@ final class Headers
     /**
      * @return $this
      */
-    public function addParameterizedHeader(string $name, string $value, array $params = [])
+    public function addParameterizedHeader(string $name, string $value, array $params = []): object
     {
         return $this->add(new ParameterizedHeader($name, $value, $params));
     }
@@ -133,7 +133,7 @@ final class Headers
     /**
      * @return $this
      */
-    public function add(HeaderInterface $header)
+    public function add(HeaderInterface $header): object
     {
         static $map = [
             'date' => DateHeader::class,
diff --git a/src/Symfony/Component/Mime/Header/IdentificationHeader.php b/src/Symfony/Component/Mime/Header/IdentificationHeader.php
index 0695b688da..eedc34ac8e 100644
--- a/src/Symfony/Component/Mime/Header/IdentificationHeader.php
+++ b/src/Symfony/Component/Mime/Header/IdentificationHeader.php
@@ -46,10 +46,7 @@ final class IdentificationHeader extends AbstractHeader
         $this->setId($body);
     }
 
-    /**
-     * @return array
-     */
-    public function getBody()
+    public function getBody(): array
     {
         return $this->getIds();
     }
diff --git a/src/Symfony/Component/Mime/Header/MailboxHeader.php b/src/Symfony/Component/Mime/Header/MailboxHeader.php
index c4f48f3e48..96a3b162f6 100644
--- a/src/Symfony/Component/Mime/Header/MailboxHeader.php
+++ b/src/Symfony/Component/Mime/Header/MailboxHeader.php
@@ -45,10 +45,8 @@ final class MailboxHeader extends AbstractHeader
 
     /**
      * @throws RfcComplianceException
-     *
-     * @return Address
      */
-    public function getBody()
+    public function getBody(): Address
     {
         return $this->getAddress();
     }
diff --git a/src/Symfony/Component/Mime/Header/MailboxListHeader.php b/src/Symfony/Component/Mime/Header/MailboxListHeader.php
index 51af2da87c..8d82cdee54 100644
--- a/src/Symfony/Component/Mime/Header/MailboxListHeader.php
+++ b/src/Symfony/Component/Mime/Header/MailboxListHeader.php
@@ -51,7 +51,7 @@ final class MailboxListHeader extends AbstractHeader
      *
      * @return (NamedAddress|Address)[]
      */
-    public function getBody()
+    public function getBody(): array
     {
         return $this->getAddresses();
     }
diff --git a/src/Symfony/Component/Mime/Header/PathHeader.php b/src/Symfony/Component/Mime/Header/PathHeader.php
index 6d16500a18..0ac61aa8eb 100644
--- a/src/Symfony/Component/Mime/Header/PathHeader.php
+++ b/src/Symfony/Component/Mime/Header/PathHeader.php
@@ -42,10 +42,7 @@ final class PathHeader extends AbstractHeader
         $this->setAddress($body);
     }
 
-    /**
-     * @return Address
-     */
-    public function getBody()
+    public function getBody(): Address
     {
         return $this->getAddress();
     }
diff --git a/src/Symfony/Component/Mime/RawMessage.php b/src/Symfony/Component/Mime/RawMessage.php
index 16b090c954..f03d828342 100644
--- a/src/Symfony/Component/Mime/RawMessage.php
+++ b/src/Symfony/Component/Mime/RawMessage.php
@@ -56,7 +56,7 @@ class RawMessage implements \Serializable
     /**
      * @internal
      */
-    final public function serialize()
+    final public function serialize(): string
     {
         return serialize($this->__serialize());
     }
diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
index 3926983a38..9a41864564 100644
--- a/src/Symfony/Component/Process/Process.php
+++ b/src/Symfony/Component/Process/Process.php
@@ -246,7 +246,7 @@ class Process implements \IteratorAggregate
      *
      * @final
      */
-    public function mustRun(callable $callback = null, array $env = [])
+    public function mustRun(callable $callback = null, array $env = []): object
     {
         if (0 !== $this->run($callback, $env)) {
             throw new ProcessFailedException($this);
@@ -367,7 +367,7 @@ class Process implements \IteratorAggregate
      *
      * @final
      */
-    public function restart(callable $callback = null, array $env = [])
+    public function restart(callable $callback = null, array $env = []): object
     {
         if ($this->isRunning()) {
             throw new RuntimeException('Process is already running');
diff --git a/src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php b/src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php
index c56dbdc2cb..3b0c01a2d9 100644
--- a/src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php
+++ b/src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php
@@ -156,7 +156,7 @@ class ReflectionExtractor implements PropertyListExtractorInterface, PropertyTyp
     /**
      * {@inheritdoc}
      */
-    public function isReadable($class, $property, array $context = [])
+    public function isReadable($class, $property, array $context = []): bool
     {
         if ($this->isAllowedProperty($class, $property)) {
             return true;
@@ -170,7 +170,7 @@ class ReflectionExtractor implements PropertyListExtractorInterface, PropertyTyp
     /**
      * {@inheritdoc}
      */
-    public function isWritable($class, $property, array $context = [])
+    public function isWritable($class, $property, array $context = []): bool
     {
         if ($this->isAllowedProperty($class, $property)) {
             return true;
@@ -292,7 +292,7 @@ class ReflectionExtractor implements PropertyListExtractorInterface, PropertyTyp
         return null;
     }
 
-    private function extractFromDefaultValue(string $class, string $property)
+    private function extractFromDefaultValue(string $class, string $property): ?array
     {
         try {
             $reflectionClass = new \ReflectionClass($class);
diff --git a/src/Symfony/Component/Routing/CompiledRoute.php b/src/Symfony/Component/Routing/CompiledRoute.php
index d46a4de632..9ffd1b5391 100644
--- a/src/Symfony/Component/Routing/CompiledRoute.php
+++ b/src/Symfony/Component/Routing/CompiledRoute.php
@@ -66,7 +66,7 @@ class CompiledRoute implements \Serializable
     /**
      * @internal
      */
-    final public function serialize()
+    final public function serialize(): string
     {
         return serialize($this->__serialize());
     }
diff --git a/src/Symfony/Component/Routing/Loader/Configurator/CollectionConfigurator.php b/src/Symfony/Component/Routing/Loader/Configurator/CollectionConfigurator.php
index e1de75e01d..a4663b5ab3 100644
--- a/src/Symfony/Component/Routing/Loader/Configurator/CollectionConfigurator.php
+++ b/src/Symfony/Component/Routing/Loader/Configurator/CollectionConfigurator.php
@@ -47,10 +47,8 @@ class CollectionConfigurator
 
     /**
      * Creates a sub-collection.
-     *
-     * @return self
      */
-    final public function collection($name = '')
+    final public function collection($name = ''): self
     {
         return new self($this->collection, $this->name.$name, $this, $this->prefixes);
     }
@@ -62,7 +60,7 @@ class CollectionConfigurator
      *
      * @return $this
      */
-    final public function prefix($prefix)
+    final public function prefix($prefix): object
     {
         if (\is_array($prefix)) {
             if (null === $this->parentPrefixes) {
diff --git a/src/Symfony/Component/Routing/Loader/Configurator/ImportConfigurator.php b/src/Symfony/Component/Routing/Loader/Configurator/ImportConfigurator.php
index 92e7efde46..b351c5364e 100644
--- a/src/Symfony/Component/Routing/Loader/Configurator/ImportConfigurator.php
+++ b/src/Symfony/Component/Routing/Loader/Configurator/ImportConfigurator.php
@@ -41,7 +41,7 @@ class ImportConfigurator
      *
      * @return $this
      */
-    final public function prefix($prefix, bool $trailingSlashOnRoot = true)
+    final public function prefix($prefix, bool $trailingSlashOnRoot = true): object
     {
         if (!\is_array($prefix)) {
             $this->route->addPrefix($prefix);
@@ -84,7 +84,7 @@ class ImportConfigurator
      *
      * @return $this
      */
-    final public function namePrefix(string $namePrefix)
+    final public function namePrefix(string $namePrefix): object
     {
         $this->route->addNamePrefix($namePrefix);
 
diff --git a/src/Symfony/Component/Routing/Loader/Configurator/RoutingConfigurator.php b/src/Symfony/Component/Routing/Loader/Configurator/RoutingConfigurator.php
index a315cfb4ad..f9c347e81a 100644
--- a/src/Symfony/Component/Routing/Loader/Configurator/RoutingConfigurator.php
+++ b/src/Symfony/Component/Routing/Loader/Configurator/RoutingConfigurator.php
@@ -33,10 +33,7 @@ class RoutingConfigurator
         $this->file = $file;
     }
 
-    /**
-     * @return ImportConfigurator
-     */
-    final public function import($resource, $type = null, $ignoreErrors = false)
+    final public function import($resource, $type = null, $ignoreErrors = false): ImportConfigurator
     {
         $this->loader->setCurrentDir(\dirname($this->path));
         $imported = $this->loader->import($resource, $type, $ignoreErrors, $this->file);
@@ -52,10 +49,7 @@ class RoutingConfigurator
         return new ImportConfigurator($this->collection, $mergedCollection);
     }
 
-    /**
-     * @return CollectionConfigurator
-     */
-    final public function collection($name = '')
+    final public function collection($name = ''): CollectionConfigurator
     {
         return new CollectionConfigurator($this->collection, $name);
     }
diff --git a/src/Symfony/Component/Routing/Loader/Configurator/Traits/RouteTrait.php b/src/Symfony/Component/Routing/Loader/Configurator/Traits/RouteTrait.php
index 92c4d2ffdc..aebfa9388f 100644
--- a/src/Symfony/Component/Routing/Loader/Configurator/Traits/RouteTrait.php
+++ b/src/Symfony/Component/Routing/Loader/Configurator/Traits/RouteTrait.php
@@ -26,7 +26,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function defaults(array $defaults)
+    final public function defaults(array $defaults): object
     {
         $this->route->addDefaults($defaults);
 
@@ -38,7 +38,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function requirements(array $requirements)
+    final public function requirements(array $requirements): object
     {
         $this->route->addRequirements($requirements);
 
@@ -50,7 +50,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function options(array $options)
+    final public function options(array $options): object
     {
         $this->route->addOptions($options);
 
@@ -62,7 +62,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function utf8(bool $utf8 = true)
+    final public function utf8(bool $utf8 = true): object
     {
         $this->route->addOptions(['utf8' => $utf8]);
 
@@ -74,7 +74,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function condition(string $condition)
+    final public function condition(string $condition): object
     {
         $this->route->setCondition($condition);
 
@@ -86,7 +86,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function host(string $pattern)
+    final public function host(string $pattern): object
     {
         $this->route->setHost($pattern);
 
@@ -101,7 +101,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function schemes(array $schemes)
+    final public function schemes(array $schemes): object
     {
         $this->route->setSchemes($schemes);
 
@@ -116,7 +116,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function methods(array $methods)
+    final public function methods(array $methods): object
     {
         $this->route->setMethods($methods);
 
@@ -130,7 +130,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function controller($controller)
+    final public function controller($controller): object
     {
         $this->route->addDefaults(['_controller' => $controller]);
 
@@ -142,7 +142,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function locale(string $locale)
+    final public function locale(string $locale): object
     {
         $this->route->addDefaults(['_locale' => $locale]);
 
@@ -154,7 +154,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function format(string $format)
+    final public function format(string $format): object
     {
         $this->route->addDefaults(['_format' => $format]);
 
diff --git a/src/Symfony/Component/Routing/Route.php b/src/Symfony/Component/Routing/Route.php
index 8fc95410d0..a4e7787228 100644
--- a/src/Symfony/Component/Routing/Route.php
+++ b/src/Symfony/Component/Routing/Route.php
@@ -80,7 +80,7 @@ class Route implements \Serializable
     /**
      * @internal
      */
-    final public function serialize()
+    final public function serialize(): string
     {
         return serialize($this->__serialize());
     }
diff --git a/src/Symfony/Component/Security/Core/Authentication/RememberMe/PersistentToken.php b/src/Symfony/Component/Security/Core/Authentication/RememberMe/PersistentToken.php
index 7c12706e3c..1f0e485c50 100644
--- a/src/Symfony/Component/Security/Core/Authentication/RememberMe/PersistentToken.php
+++ b/src/Symfony/Component/Security/Core/Authentication/RememberMe/PersistentToken.php
@@ -49,7 +49,7 @@ final class PersistentToken implements PersistentTokenInterface
     /**
      * {@inheritdoc}
      */
-    public function getClass()
+    public function getClass(): string
     {
         return $this->class;
     }
@@ -57,7 +57,7 @@ final class PersistentToken implements PersistentTokenInterface
     /**
      * {@inheritdoc}
      */
-    public function getUsername()
+    public function getUsername(): string
     {
         return $this->username;
     }
@@ -65,7 +65,7 @@ final class PersistentToken implements PersistentTokenInterface
     /**
      * {@inheritdoc}
      */
-    public function getSeries()
+    public function getSeries(): string
     {
         return $this->series;
     }
@@ -73,7 +73,7 @@ final class PersistentToken implements PersistentTokenInterface
     /**
      * {@inheritdoc}
      */
-    public function getTokenValue()
+    public function getTokenValue(): string
     {
         return $this->tokenValue;
     }
@@ -81,7 +81,7 @@ final class PersistentToken implements PersistentTokenInterface
     /**
      * {@inheritdoc}
      */
-    public function getLastUsed()
+    public function getLastUsed(): \DateTime
     {
         return $this->lastUsed;
     }
diff --git a/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php b/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
index 5e92fa4900..1e9dbe82df 100644
--- a/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
+++ b/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
@@ -244,7 +244,7 @@ abstract class AbstractToken implements TokenInterface
     /**
      * @internal
      */
-    final public function serialize()
+    final public function serialize(): string
     {
         return serialize($this->__serialize());
     }
diff --git a/src/Symfony/Component/Security/Core/Authorization/AuthorizationChecker.php b/src/Symfony/Component/Security/Core/Authorization/AuthorizationChecker.php
index db30095743..3200e991df 100644
--- a/src/Symfony/Component/Security/Core/Authorization/AuthorizationChecker.php
+++ b/src/Symfony/Component/Security/Core/Authorization/AuthorizationChecker.php
@@ -43,7 +43,7 @@ class AuthorizationChecker implements AuthorizationCheckerInterface
      *
      * @throws AuthenticationCredentialsNotFoundException when the token storage has no authentication token
      */
-    final public function isGranted($attributes, $subject = null)
+    final public function isGranted($attributes, $subject = null): bool
     {
         if (null === ($token = $this->tokenStorage->getToken())) {
             throw new AuthenticationCredentialsNotFoundException('The token storage contains no authentication token. One possible reason may be that there is no firewall configured for this URL.');
diff --git a/src/Symfony/Component/Security/Core/Encoder/MigratingPasswordEncoder.php b/src/Symfony/Component/Security/Core/Encoder/MigratingPasswordEncoder.php
index 77e6726808..2c8a6f72ce 100644
--- a/src/Symfony/Component/Security/Core/Encoder/MigratingPasswordEncoder.php
+++ b/src/Symfony/Component/Security/Core/Encoder/MigratingPasswordEncoder.php
@@ -34,7 +34,7 @@ final class MigratingPasswordEncoder extends BasePasswordEncoder implements Self
     /**
      * {@inheritdoc}
      */
-    public function encodePassword($raw, $salt)
+    public function encodePassword($raw, $salt): string
     {
         return $this->bestEncoder->encodePassword($raw, $salt);
     }
@@ -42,7 +42,7 @@ final class MigratingPasswordEncoder extends BasePasswordEncoder implements Self
     /**
      * {@inheritdoc}
      */
-    public function isPasswordValid($encoded, $raw, $salt)
+    public function isPasswordValid($encoded, $raw, $salt): bool
     {
         if ($this->bestEncoder->isPasswordValid($encoded, $raw, $salt)) {
             return true;
diff --git a/src/Symfony/Component/Security/Core/Encoder/NativePasswordEncoder.php b/src/Symfony/Component/Security/Core/Encoder/NativePasswordEncoder.php
index a05eb288e5..b20bf4f876 100644
--- a/src/Symfony/Component/Security/Core/Encoder/NativePasswordEncoder.php
+++ b/src/Symfony/Component/Security/Core/Encoder/NativePasswordEncoder.php
@@ -78,7 +78,7 @@ final class NativePasswordEncoder implements PasswordEncoderInterface, SelfSalti
     /**
      * {@inheritdoc}
      */
-    public function isPasswordValid($encoded, $raw, $salt)
+    public function isPasswordValid($encoded, $raw, $salt): bool
     {
         if (72 < \strlen($raw) && 0 === strpos($encoded, '$2')) {
             // BCrypt encodes only the first 72 chars
diff --git a/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php b/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php
index 82cb1e17dd..4630aa3b03 100644
--- a/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php
+++ b/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php
@@ -58,7 +58,7 @@ final class SodiumPasswordEncoder implements PasswordEncoderInterface, SelfSalti
     /**
      * {@inheritdoc}
      */
-    public function encodePassword($raw, $salt)
+    public function encodePassword($raw, $salt): string
     {
         if (\strlen($raw) > self::MAX_PASSWORD_LENGTH) {
             throw new BadCredentialsException('Invalid password.');
@@ -78,7 +78,7 @@ final class SodiumPasswordEncoder implements PasswordEncoderInterface, SelfSalti
     /**
      * {@inheritdoc}
      */
-    public function isPasswordValid($encoded, $raw, $salt)
+    public function isPasswordValid($encoded, $raw, $salt): bool
     {
         if (\strlen($raw) > self::MAX_PASSWORD_LENGTH) {
             return false;
diff --git a/src/Symfony/Component/Security/Core/Security.php b/src/Symfony/Component/Security/Core/Security.php
index 4ba8cefef9..90805de9ee 100644
--- a/src/Symfony/Component/Security/Core/Security.php
+++ b/src/Symfony/Component/Security/Core/Security.php
@@ -34,10 +34,7 @@ class Security
         $this->container = $container;
     }
 
-    /**
-     * @return UserInterface|null
-     */
-    public function getUser()
+    public function getUser(): ?UserInterface
     {
         if (!$token = $this->getToken()) {
             return null;
@@ -60,19 +57,14 @@ class Security
      *
      * @param mixed $attributes
      * @param mixed $subject
-     *
-     * @return bool
      */
-    public function isGranted($attributes, $subject = null)
+    public function isGranted($attributes, $subject = null): bool
     {
         return $this->container->get('security.authorization_checker')
             ->isGranted($attributes, $subject);
     }
 
-    /**
-     * @return TokenInterface|null
-     */
-    public function getToken()
+    public function getToken(): ?TokenInterface
     {
         return $this->container->get('security.token_storage')->getToken();
     }
diff --git a/src/Symfony/Component/Security/Core/User/User.php b/src/Symfony/Component/Security/Core/User/User.php
index dca5c4fe2b..ef0ae2f303 100644
--- a/src/Symfony/Component/Security/Core/User/User.php
+++ b/src/Symfony/Component/Security/Core/User/User.php
@@ -43,7 +43,7 @@ final class User implements UserInterface, EquatableInterface
         $this->roles = $roles;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         return $this->getUsername();
     }
@@ -51,7 +51,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function getRoles()
+    public function getRoles(): array
     {
         return $this->roles;
     }
@@ -59,7 +59,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function getPassword()
+    public function getPassword(): ?string
     {
         return $this->password;
     }
@@ -74,7 +74,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function getUsername()
+    public function getUsername(): string
     {
         return $this->username;
     }
@@ -82,7 +82,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function isAccountNonExpired()
+    public function isAccountNonExpired(): bool
     {
         return $this->accountNonExpired;
     }
@@ -90,7 +90,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function isAccountNonLocked()
+    public function isAccountNonLocked(): bool
     {
         return $this->accountNonLocked;
     }
@@ -98,7 +98,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function isCredentialsNonExpired()
+    public function isCredentialsNonExpired(): bool
     {
         return $this->credentialsNonExpired;
     }
@@ -106,7 +106,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function isEnabled()
+    public function isEnabled(): bool
     {
         return $this->enabled;
     }
@@ -121,7 +121,7 @@ final class User implements UserInterface, EquatableInterface
     /**
      * {@inheritdoc}
      */
-    public function isEqualTo(UserInterface $user)
+    public function isEqualTo(UserInterface $user): bool
     {
         if (!$user instanceof self) {
             return false;
diff --git a/src/Symfony/Component/Security/Http/Controller/UserValueResolver.php b/src/Symfony/Component/Security/Http/Controller/UserValueResolver.php
index 221d8d8ead..7774e7b4a2 100644
--- a/src/Symfony/Component/Security/Http/Controller/UserValueResolver.php
+++ b/src/Symfony/Component/Security/Http/Controller/UserValueResolver.php
@@ -32,7 +32,7 @@ final class UserValueResolver implements ArgumentValueResolverInterface
         $this->tokenStorage = $tokenStorage;
     }
 
-    public function supports(Request $request, ArgumentMetadata $argument)
+    public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         // only security user implementations are supported
         if (UserInterface::class !== $argument->getType()) {
@@ -50,7 +50,7 @@ final class UserValueResolver implements ArgumentValueResolverInterface
         return $user instanceof UserInterface;
     }
 
-    public function resolve(Request $request, ArgumentMetadata $argument)
+    public function resolve(Request $request, ArgumentMetadata $argument): iterable
     {
         yield $this->tokenStorage->getToken()->getUser();
     }
diff --git a/src/Symfony/Component/Security/Http/Firewall/ContextListener.php b/src/Symfony/Component/Security/Http/Firewall/ContextListener.php
index 8d626a1aed..470d2a8dc4 100644
--- a/src/Symfony/Component/Security/Http/Firewall/ContextListener.php
+++ b/src/Symfony/Component/Security/Http/Firewall/ContextListener.php
@@ -140,11 +140,9 @@ class ContextListener
     /**
      * Refreshes the user by reloading it from the user provider.
      *
-     * @return TokenInterface|null
-     *
      * @throws \RuntimeException
      */
-    protected function refreshUser(TokenInterface $token)
+    protected function refreshUser(TokenInterface $token): ?TokenInterface
     {
         $user = $token->getUser();
         if (!$user instanceof UserInterface) {
diff --git a/src/Symfony/Component/Security/Http/Firewall/LogoutListener.php b/src/Symfony/Component/Security/Http/Firewall/LogoutListener.php
index 5ec26e7fc4..e915502e98 100644
--- a/src/Symfony/Component/Security/Http/Firewall/LogoutListener.php
+++ b/src/Symfony/Component/Security/Http/Firewall/LogoutListener.php
@@ -113,10 +113,8 @@ class LogoutListener
      * The default implementation only processed requests to a specific path,
      * but a subclass could change this to logout requests where
      * certain parameters is present.
-     *
-     * @return bool
      */
-    protected function requiresLogout(Request $request)
+    protected function requiresLogout(Request $request): bool
     {
         return isset($this->options['logout_path']) && $this->httpUtils->checkRequestPath($request, $this->options['logout_path']);
     }
diff --git a/src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php b/src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php
index d591d846dc..bbe82db233 100644
--- a/src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php
+++ b/src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php
@@ -118,7 +118,7 @@ class SwitchUserListener
      * @throws \LogicException
      * @throws AccessDeniedException
      */
-    private function attemptSwitchUser(Request $request, $username)
+    private function attemptSwitchUser(Request $request, $username): ?TokenInterface
     {
         $token = $this->tokenStorage->getToken();
         $originalToken = $this->getOriginalToken($token);
@@ -167,7 +167,7 @@ class SwitchUserListener
      *
      * @throws AuthenticationCredentialsNotFoundException
      */
-    private function attemptExitUser(Request $request)
+    private function attemptExitUser(Request $request): TokenInterface
     {
         if (null === ($currentToken = $this->tokenStorage->getToken()) || null === $original = $this->getOriginalToken($currentToken)) {
             throw new AuthenticationCredentialsNotFoundException('Could not find original Token object.');
diff --git a/src/Symfony/Component/Security/Http/RememberMe/ResponseListener.php b/src/Symfony/Component/Security/Http/RememberMe/ResponseListener.php
index 66fdc3fc0b..dcbb7218a2 100644
--- a/src/Symfony/Component/Security/Http/RememberMe/ResponseListener.php
+++ b/src/Symfony/Component/Security/Http/RememberMe/ResponseListener.php
@@ -41,7 +41,7 @@ class ResponseListener implements EventSubscriberInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [KernelEvents::RESPONSE => 'onKernelResponse'];
     }
diff --git a/src/Symfony/Component/Serializer/Encoder/ChainDecoder.php b/src/Symfony/Component/Serializer/Encoder/ChainDecoder.php
index 0100a6282f..2a55d93a60 100644
--- a/src/Symfony/Component/Serializer/Encoder/ChainDecoder.php
+++ b/src/Symfony/Component/Serializer/Encoder/ChainDecoder.php
@@ -43,7 +43,7 @@ class ChainDecoder implements ContextAwareDecoderInterface
     /**
      * {@inheritdoc}
      */
-    public function supportsDecoding($format, array $context = [])
+    public function supportsDecoding($format, array $context = []): bool
     {
         try {
             $this->getDecoder($format, $context);
diff --git a/src/Symfony/Component/Serializer/Encoder/ChainEncoder.php b/src/Symfony/Component/Serializer/Encoder/ChainEncoder.php
index eb1b84ad3c..8bf2dfe6ef 100644
--- a/src/Symfony/Component/Serializer/Encoder/ChainEncoder.php
+++ b/src/Symfony/Component/Serializer/Encoder/ChainEncoder.php
@@ -43,7 +43,7 @@ class ChainEncoder implements ContextAwareEncoderInterface
     /**
      * {@inheritdoc}
      */
-    public function supportsEncoding($format, array $context = [])
+    public function supportsEncoding($format, array $context = []): bool
     {
         try {
             $this->getEncoder($format, $context);
@@ -59,10 +59,8 @@ class ChainEncoder implements ContextAwareEncoderInterface
      *
      * @param string $format
      * @param array  $context
-     *
-     * @return bool
      */
-    public function needsNormalization($format, array $context = [])
+    public function needsNormalization($format, array $context = []): bool
     {
         $encoder = $this->getEncoder($format, $context);
 
diff --git a/src/Symfony/Component/Serializer/NameConverter/MetadataAwareNameConverter.php b/src/Symfony/Component/Serializer/NameConverter/MetadataAwareNameConverter.php
index e863e013e7..1fef5507ff 100644
--- a/src/Symfony/Component/Serializer/NameConverter/MetadataAwareNameConverter.php
+++ b/src/Symfony/Component/Serializer/NameConverter/MetadataAwareNameConverter.php
@@ -40,7 +40,7 @@ final class MetadataAwareNameConverter implements AdvancedNameConverterInterface
     /**
      * {@inheritdoc}
      */
-    public function normalize($propertyName, string $class = null, string $format = null, array $context = [])
+    public function normalize($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         if (null === $class) {
             return $this->normalizeFallback($propertyName, $class, $format, $context);
@@ -56,7 +56,7 @@ final class MetadataAwareNameConverter implements AdvancedNameConverterInterface
     /**
      * {@inheritdoc}
      */
-    public function denormalize($propertyName, string $class = null, string $format = null, array $context = [])
+    public function denormalize($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         if (null === $class) {
             return $this->denormalizeFallback($propertyName, $class, $format, $context);
@@ -69,7 +69,7 @@ final class MetadataAwareNameConverter implements AdvancedNameConverterInterface
         return self::$denormalizeCache[$class][$propertyName] ?? $this->denormalizeFallback($propertyName, $class, $format, $context);
     }
 
-    private function getCacheValueForNormalization($propertyName, string $class)
+    private function getCacheValueForNormalization($propertyName, string $class): ?string
     {
         if (!$this->metadataFactory->hasMetadataFor($class)) {
             return null;
@@ -83,12 +83,12 @@ final class MetadataAwareNameConverter implements AdvancedNameConverterInterface
         return $attributesMetadata[$propertyName]->getSerializedName() ?? null;
     }
 
-    private function normalizeFallback($propertyName, string $class = null, string $format = null, array $context = [])
+    private function normalizeFallback($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         return $this->fallbackNameConverter ? $this->fallbackNameConverter->normalize($propertyName, $class, $format, $context) : $propertyName;
     }
 
-    private function getCacheValueForDenormalization($propertyName, string $class)
+    private function getCacheValueForDenormalization($propertyName, string $class): ?string
     {
         if (!isset(self::$attributesMetadataCache[$class])) {
             self::$attributesMetadataCache[$class] = $this->getCacheValueForAttributesMetadata($class);
@@ -97,7 +97,7 @@ final class MetadataAwareNameConverter implements AdvancedNameConverterInterface
         return self::$attributesMetadataCache[$class][$propertyName] ?? null;
     }
 
-    private function denormalizeFallback($propertyName, string $class = null, string $format = null, array $context = [])
+    private function denormalizeFallback($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         return $this->fallbackNameConverter ? $this->fallbackNameConverter->denormalize($propertyName, $class, $format, $context) : $propertyName;
     }
diff --git a/src/Symfony/Component/Serializer/Tests/NameConverter/MetadataAwareNameConverterTest.php b/src/Symfony/Component/Serializer/Tests/NameConverter/MetadataAwareNameConverterTest.php
index 7e2552ea8a..b78050e484 100644
--- a/src/Symfony/Component/Serializer/Tests/NameConverter/MetadataAwareNameConverterTest.php
+++ b/src/Symfony/Component/Serializer/Tests/NameConverter/MetadataAwareNameConverterTest.php
@@ -96,7 +96,7 @@ final class MetadataAwareNameConverterTest extends TestCase
         $this->assertEquals($expected, $nameConverter->denormalize($propertyName, SerializedNameDummy::class));
     }
 
-    public function attributeProvider()
+    public function attributeProvider(): array
     {
         return [
             ['foo', 'baz'],
@@ -106,7 +106,7 @@ final class MetadataAwareNameConverterTest extends TestCase
         ];
     }
 
-    public function fallbackAttributeProvider()
+    public function fallbackAttributeProvider(): array
     {
         return [
             ['foo', 'baz'],
diff --git a/src/Symfony/Component/Validator/Mapping/Cache/DoctrineCache.php b/src/Symfony/Component/Validator/Mapping/Cache/DoctrineCache.php
index 36f1febc5a..2f54019328 100644
--- a/src/Symfony/Component/Validator/Mapping/Cache/DoctrineCache.php
+++ b/src/Symfony/Component/Validator/Mapping/Cache/DoctrineCache.php
@@ -36,7 +36,7 @@ final class DoctrineCache implements CacheInterface
     /**
      * {@inheritdoc}
      */
-    public function has($class)
+    public function has($class): bool
     {
         return $this->cache->contains($class);
     }
diff --git a/src/Symfony/Component/Validator/Mapping/Loader/PropertyInfoLoader.php b/src/Symfony/Component/Validator/Mapping/Loader/PropertyInfoLoader.php
index 7ddd534275..379210b54b 100644
--- a/src/Symfony/Component/Validator/Mapping/Loader/PropertyInfoLoader.php
+++ b/src/Symfony/Component/Validator/Mapping/Loader/PropertyInfoLoader.php
@@ -44,7 +44,7 @@ final class PropertyInfoLoader implements LoaderInterface
     /**
      * {@inheritdoc}
      */
-    public function loadClassMetadata(ClassMetadata $metadata)
+    public function loadClassMetadata(ClassMetadata $metadata): bool
     {
         $className = $metadata->getClassName();
         if (null !== $this->classValidatorRegexp && !preg_match($this->classValidatorRegexp, $className)) {
diff --git a/src/Symfony/Component/VarDumper/Caster/Caster.php b/src/Symfony/Component/VarDumper/Caster/Caster.php
index a8a7e21247..fcc2322de0 100644
--- a/src/Symfony/Component/VarDumper/Caster/Caster.php
+++ b/src/Symfony/Component/VarDumper/Caster/Caster.php
@@ -46,7 +46,7 @@ class Caster
      *
      * @return array The array-cast of the object, with prefixed dynamic properties
      */
-    public static function castObject($obj, $class, $hasDebugInfo = false)
+    public static function castObject($obj, $class, $hasDebugInfo = false): array
     {
         if ($hasDebugInfo) {
             $a = $obj->__debugInfo();
@@ -104,7 +104,7 @@ class Caster
      *
      * @return array The filtered array
      */
-    public static function filter(array $a, $filter, array $listedProperties = [], &$count = 0)
+    public static function filter(array $a, $filter, array $listedProperties = [], &$count = 0): array
     {
         $count = 0;
 
@@ -145,13 +145,14 @@ class Caster
         return $a;
     }
 
-    public static function castPhpIncompleteClass(\__PHP_Incomplete_Class $c, array $a, Stub $stub, $isNested)
+    public static function castPhpIncompleteClass(\__PHP_Incomplete_Class $c, array $a, Stub $stub, $isNested): array
     {
         if (isset($a['__PHP_Incomplete_Class_Name'])) {
             $stub->class .= '('.$a['__PHP_Incomplete_Class_Name'].')';
             unset($a['__PHP_Incomplete_Class_Name']);
         }
 
+
         return $a;
     }
 }
diff --git a/src/Symfony/Component/VarExporter/Instantiator.php b/src/Symfony/Component/VarExporter/Instantiator.php
index 06abbc75a6..9fd8cf3722 100644
--- a/src/Symfony/Component/VarExporter/Instantiator.php
+++ b/src/Symfony/Component/VarExporter/Instantiator.php
@@ -57,7 +57,7 @@ final class Instantiator
      *
      * @throws ExceptionInterface When the instance cannot be created
      */
-    public static function instantiate(string $class, array $properties = [], array $privateProperties = [])
+    public static function instantiate(string $class, array $properties = [], array $privateProperties = []): object
     {
         $reflector = Registry::$reflectors[$class] ?? Registry::getClassReflector($class);
 
diff --git a/src/Symfony/Component/VarExporter/Tests/VarExporterTest.php b/src/Symfony/Component/VarExporter/Tests/VarExporterTest.php
index 6f54d76106..78ef7ed80a 100644
--- a/src/Symfony/Component/VarExporter/Tests/VarExporterTest.php
+++ b/src/Symfony/Component/VarExporter/Tests/VarExporterTest.php
@@ -322,7 +322,7 @@ final class FinalError extends \Error
 
 final class FinalArrayIterator extends \ArrayIterator
 {
-    public function serialize()
+    public function serialize(): string
     {
         return serialize([123, parent::serialize()]);
     }
diff --git a/src/Symfony/Component/WebLink/EventListener/AddLinkHeaderListener.php b/src/Symfony/Component/WebLink/EventListener/AddLinkHeaderListener.php
index d743f4664c..3027529a84 100644
--- a/src/Symfony/Component/WebLink/EventListener/AddLinkHeaderListener.php
+++ b/src/Symfony/Component/WebLink/EventListener/AddLinkHeaderListener.php
@@ -50,7 +50,7 @@ class AddLinkHeaderListener implements EventSubscriberInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [KernelEvents::RESPONSE => 'onKernelResponse'];
     }
diff --git a/src/Symfony/Component/WebLink/HttpHeaderSerializer.php b/src/Symfony/Component/WebLink/HttpHeaderSerializer.php
index 6c7a039326..d80d96ec3b 100644
--- a/src/Symfony/Component/WebLink/HttpHeaderSerializer.php
+++ b/src/Symfony/Component/WebLink/HttpHeaderSerializer.php
@@ -26,10 +26,8 @@ final class HttpHeaderSerializer
      * Builds the value of the "Link" HTTP header.
      *
      * @param LinkInterface[]|\Traversable $links
-     *
-     * @return string|null
      */
-    public function serialize(iterable $links)
+    public function serialize(iterable $links): ?string
     {
         $elements = [];
         foreach ($links as $link) {
diff --git a/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php b/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
index a2341aadbd..df1a6a24ab 100644
--- a/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
+++ b/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
@@ -46,7 +46,7 @@ final class MethodMarkingStore implements MarkingStoreInterface
     /**
      * {@inheritdoc}
      */
-    public function getMarking($subject)
+    public function getMarking($subject): Marking
     {
         $method = 'get'.ucfirst($this->property);
 
diff --git a/src/Symfony/Component/Workflow/TransitionBlockerList.php b/src/Symfony/Component/Workflow/TransitionBlockerList.php
index 8569b28fea..f7f4a63ea3 100644
--- a/src/Symfony/Component/Workflow/TransitionBlockerList.php
+++ b/src/Symfony/Component/Workflow/TransitionBlockerList.php
@@ -63,7 +63,7 @@ final class TransitionBlockerList implements \IteratorAggregate, \Countable
      *
      * @return \ArrayIterator|TransitionBlocker[]
      */
-    public function getIterator()
+    public function getIterator(): \Traversable
     {
         return new \ArrayIterator($this->blockers);
     }