diff --git a/src/Symfony/Bridge/Twig/Command/DebugCommand.php b/src/Symfony/Bridge/Twig/Command/DebugCommand.php
index fa142d381e..17bbd845b2 100644
--- a/src/Symfony/Bridge/Twig/Command/DebugCommand.php
+++ b/src/Symfony/Bridge/Twig/Command/DebugCommand.php
@@ -234,7 +234,7 @@ EOF
         }
     }
 
-    private function displayGeneralJson(SymfonyStyle $io, $filter)
+    private function displayGeneralJson(SymfonyStyle $io, ?string $filter)
     {
         $decorated = $io->isDecorated();
         $types = ['functions', 'filters', 'tests', 'globals'];
@@ -288,7 +288,7 @@ EOF
         return $loaderPaths;
     }
 
-    private function getMetadata($type, $entity)
+    private function getMetadata(string $type, $entity)
     {
         if ('globals' === $type) {
             return $entity;
@@ -344,7 +344,7 @@ EOF
         }
     }
 
-    private function getPrettyMetadata($type, $entity, $decorated)
+    private function getPrettyMetadata(string $type, $entity, bool $decorated)
     {
         if ('tests' === $type) {
             return '';
diff --git a/src/Symfony/Bridge/Twig/Command/LintCommand.php b/src/Symfony/Bridge/Twig/Command/LintCommand.php
index 9ea2ff7eb6..5f066874e8 100644
--- a/src/Symfony/Bridge/Twig/Command/LintCommand.php
+++ b/src/Symfony/Bridge/Twig/Command/LintCommand.php
@@ -118,7 +118,7 @@ EOF
         throw new RuntimeException(sprintf('File or directory "%s" is not readable', $filename));
     }
 
-    private function validate($template, $file)
+    private function validate(string $template, $file)
     {
         $realLoader = $this->twig->getLoader();
         try {
@@ -136,7 +136,7 @@ EOF
         return ['template' => $template, 'file' => $file, 'valid' => true];
     }
 
-    private function display(InputInterface $input, OutputInterface $output, SymfonyStyle $io, $files)
+    private function display(InputInterface $input, OutputInterface $output, SymfonyStyle $io, array $files)
     {
         switch ($input->getOption('format')) {
             case 'txt':
@@ -148,7 +148,7 @@ EOF
         }
     }
 
-    private function displayTxt(OutputInterface $output, SymfonyStyle $io, $filesInfo)
+    private function displayTxt(OutputInterface $output, SymfonyStyle $io, array $filesInfo)
     {
         $errors = 0;
 
@@ -170,7 +170,7 @@ EOF
         return min($errors, 1);
     }
 
-    private function displayJson(OutputInterface $output, $filesInfo)
+    private function displayJson(OutputInterface $output, array $filesInfo)
     {
         $errors = 0;
 
@@ -189,7 +189,7 @@ EOF
         return min($errors, 1);
     }
 
-    private function renderException(OutputInterface $output, $template, Error $exception, $file = null)
+    private function renderException(OutputInterface $output, string $template, Error $exception, string $file = null)
     {
         $line = $exception->getTemplateLine();
 
@@ -212,7 +212,7 @@ EOF
         }
     }
 
-    private function getContext($template, $line, $context = 3)
+    private function getContext(string $template, int $line, int $context = 3)
     {
         $lines = explode("\n", $template);
 
diff --git a/src/Symfony/Bridge/Twig/DataCollector/TwigDataCollector.php b/src/Symfony/Bridge/Twig/DataCollector/TwigDataCollector.php
index b7d059daea..b766bd99bd 100644
--- a/src/Symfony/Bridge/Twig/DataCollector/TwigDataCollector.php
+++ b/src/Symfony/Bridge/Twig/DataCollector/TwigDataCollector.php
@@ -147,7 +147,7 @@ class TwigDataCollector extends DataCollector implements LateDataCollectorInterf
         return $this->profile;
     }
 
-    private function getComputedData($index)
+    private function getComputedData(string $index)
     {
         if (null === $this->computed) {
             $this->computed = $this->computeData($this->getProfile());
diff --git a/src/Symfony/Bridge/Twig/NodeVisitor/TranslationDefaultDomainNodeVisitor.php b/src/Symfony/Bridge/Twig/NodeVisitor/TranslationDefaultDomainNodeVisitor.php
index 04b68ef6be..836a343948 100644
--- a/src/Symfony/Bridge/Twig/NodeVisitor/TranslationDefaultDomainNodeVisitor.php
+++ b/src/Symfony/Bridge/Twig/NodeVisitor/TranslationDefaultDomainNodeVisitor.php
@@ -116,7 +116,7 @@ class TranslationDefaultDomainNodeVisitor extends AbstractNodeVisitor
     /**
      * @return bool
      */
-    private function isNamedArguments($arguments)
+    private function isNamedArguments(Node $arguments)
     {
         foreach ($arguments as $name => $node) {
             if (!\is_int($name)) {