diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AbstractTrait.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/AbstractTrait.php
index 57ddb480fa..82ba21d7bd 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): self
     {
         $this->definition->setAbstract($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..5c9a475609 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ArgumentTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ArgumentTrait.php
@@ -16,11 +16,9 @@ trait ArgumentTrait
     /**
      * Sets the arguments to pass to the service constructor/factory method.
      *
-     * @param array $arguments An array of arguments
-     *
      * @return $this
      */
-    final public function args(array $arguments)
+    final public function args(array $arguments): self
     {
         $this->definition->setArguments(static::processValue($arguments, true));
 
@@ -35,7 +33,7 @@ trait ArgumentTrait
      *
      * @return $this
      */
-    final public function arg($key, $value)
+    final public function arg($key, $value): self
     {
         $this->definition->setArgument($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..836f45872e 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 $autoconfigured = true): self
     {
         if ($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..2837a0201d 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): self
     {
         $this->definition->setAutowired($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..132849439e 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(string $nameOrFqcn, $valueOrRef): self
     {
         $valueOrRef = static::processValue($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..39c5ecc7d8 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(string $method, array $arguments = []): self
     {
         $this->definition->addMethodCall($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..20da791aaa 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(?string $class): self
     {
         $this->definition->setClass($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..25d363c9a6 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): self
     {
         $this->definition->setConfigurator(static::processValue($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..809838f9ba 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DecorateTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/DecorateTrait.php
@@ -18,15 +18,13 @@ trait DecorateTrait
     /**
      * Sets the service that this service is decorating.
      *
-     * @param string|null $id        The decorated service id, use null to remove decoration
-     * @param string|null $renamedId The new decorated service id
-     * @param int         $priority  The priority of decoration
+     * @param string|null $id The decorated service id, use null to remove decoration
      *
      * @return $this
      *
      * @throws InvalidArgumentException in case the decorated service id and the new decorated service id are equals
      */
-    final public function decorate($id, $renamedId = null, $priority = 0)
+    final public function decorate(?string $id, string $renamedId = null, int $priority = 0): self
     {
         $this->definition->setDecoratedService($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..b2d5b0eb78 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(string $template = null): self
     {
         $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..3834d72aca 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($factory): self
     {
         if (\is_string($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..5f42aef8fd 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FileTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/FileTrait.php
@@ -16,11 +16,9 @@ trait FileTrait
     /**
      * Sets a file to require before creating the service.
      *
-     * @param string $file A full pathname to include
-     *
      * @return $this
      */
-    final public function file($file)
+    final public function file(string $file): self
     {
         $this->definition->setFile($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..2829defb59 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): self
     {
         $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..7488a38ca2 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 $parent): self
     {
         if (!$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..10fdcfb82f 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): self
     {
         $this->definition->setProperty($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..f15756c1b5 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(): self
     {
         $this->definition->setPublic(true);
 
@@ -26,7 +26,7 @@ trait PublicTrait
     /**
      * @return $this
      */
-    final public function private()
+    final public function private(): self
     {
         $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..16fde0f294 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ShareTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/ShareTrait.php
@@ -16,11 +16,9 @@ trait ShareTrait
     /**
      * Sets if the service must be shared or not.
      *
-     * @param bool $shared Whether the service must be shared or not
-     *
      * @return $this
      */
-    final public function share($shared = true)
+    final public function share(bool $shared = true): self
     {
         $this->definition->setShared($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..cb08b1133a 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): self
     {
         $this->definition->setSynthetic($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..f4d5f002cf 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/TagTrait.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/TagTrait.php
@@ -18,14 +18,11 @@ trait TagTrait
     /**
      * Adds a tag for this definition.
      *
-     * @param string $name       The tag name
-     * @param array  $attributes An array of attributes
-     *
      * @return $this
      */
-    final public function tag($name, array $attributes = [])
+    final public function tag(string $name, array $attributes = []): self
     {
-        if (!\is_string($name) || '' === $name) {
+        if ('' === $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/Routing/Loader/Configurator/Traits/RouteTrait.php b/src/Symfony/Component/Routing/Loader/Configurator/Traits/RouteTrait.php
index 92c4d2ffdc..04009cd16d 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): self
     {
         $this->route->addDefaults($defaults);
 
@@ -38,7 +38,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function requirements(array $requirements)
+    final public function requirements(array $requirements): self
     {
         $this->route->addRequirements($requirements);
 
@@ -50,7 +50,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function options(array $options)
+    final public function options(array $options): self
     {
         $this->route->addOptions($options);
 
@@ -62,7 +62,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function utf8(bool $utf8 = true)
+    final public function utf8(bool $utf8 = true): self
     {
         $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): self
     {
         $this->route->setCondition($condition);
 
@@ -86,7 +86,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function host(string $pattern)
+    final public function host(string $pattern): self
     {
         $this->route->setHost($pattern);
 
@@ -101,7 +101,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function schemes(array $schemes)
+    final public function schemes(array $schemes): self
     {
         $this->route->setSchemes($schemes);
 
@@ -116,7 +116,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function methods(array $methods)
+    final public function methods(array $methods): self
     {
         $this->route->setMethods($methods);
 
@@ -130,7 +130,7 @@ trait RouteTrait
      *
      * @return $this
      */
-    final public function controller($controller)
+    final public function controller($controller): self
     {
         $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): self
     {
         $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): self
     {
         $this->route->addDefaults(['_format' => $format]);