diff --git a/src/Symfony/Bundle/DebugBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/DebugBundle/DependencyInjection/Configuration.php
index 3ed12fc3f692d..9843893088074 100644
--- a/src/Symfony/Bundle/DebugBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/DebugBundle/DependencyInjection/Configuration.php
@@ -24,7 +24,7 @@ class Configuration implements ConfigurationInterface
     /**
      * {@inheritdoc}
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('debug');
 
diff --git a/src/Symfony/Bundle/DebugBundle/DependencyInjection/DebugExtension.php b/src/Symfony/Bundle/DebugBundle/DependencyInjection/DebugExtension.php
index bce977e9b1197..731cc62b3116d 100644
--- a/src/Symfony/Bundle/DebugBundle/DependencyInjection/DebugExtension.php
+++ b/src/Symfony/Bundle/DebugBundle/DependencyInjection/DebugExtension.php
@@ -100,7 +100,7 @@ public function load(array $configs, ContainerBuilder $container)
     /**
      * {@inheritdoc}
      */
-    public function getXsdValidationBasePath()
+    public function getXsdValidationBasePath(): string|false
     {
         return __DIR__.'/../Resources/config/schema';
     }
@@ -108,7 +108,7 @@ public function getXsdValidationBasePath()
     /**
      * {@inheritdoc}
      */
-    public function getNamespace()
+    public function getNamespace(): string
     {
         return 'http://symfony.com/schema/dic/debug';
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AbstractPhpFileCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AbstractPhpFileCacheWarmer.php
index 17e066045a04c..f4a06a2cf1bc2 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AbstractPhpFileCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AbstractPhpFileCacheWarmer.php
@@ -32,7 +32,7 @@ public function __construct(string $phpArrayFile)
     /**
      * {@inheritdoc}
      */
-    public function isOptional()
+    public function isOptional(): bool
     {
         return true;
     }
@@ -42,7 +42,7 @@ public function isOptional()
      *
      * @return string[] A list of classes to preload on PHP 7.4+
      */
-    public function warmUp(string $cacheDir)
+    public function warmUp(string $cacheDir): array
     {
         $arrayAdapter = new ArrayAdapter();
 
@@ -66,7 +66,7 @@ public function warmUp(string $cacheDir)
     /**
      * @return string[] A list of classes to preload on PHP 7.4+
      */
-    protected function warmUpPhpArrayAdapter(PhpArrayAdapter $phpArrayAdapter, array $values)
+    protected function warmUpPhpArrayAdapter(PhpArrayAdapter $phpArrayAdapter, array $values): array
     {
         return (array) $phpArrayAdapter->warmUp($values);
     }
@@ -85,5 +85,5 @@ final protected function ignoreAutoloadException(string $class, \Exception $exce
     /**
      * @return bool false if there is nothing to warm-up
      */
-    abstract protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter);
+    abstract protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter): bool;
 }
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AnnotationsCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AnnotationsCacheWarmer.php
index 3606b9e8ea8ce..c060959804dfc 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AnnotationsCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AnnotationsCacheWarmer.php
@@ -45,7 +45,7 @@ public function __construct(Reader $annotationReader, string $phpArrayFile, stri
     /**
      * {@inheritdoc}
      */
-    protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter)
+    protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter): bool
     {
         $annotatedClassPatterns = $cacheDir.'/annotations.map';
 
@@ -76,7 +76,7 @@ protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter)
     /**
      * @return string[] A list of classes to preload on PHP 7.4+
      */
-    protected function warmUpPhpArrayAdapter(PhpArrayAdapter $phpArrayAdapter, array $values)
+    protected function warmUpPhpArrayAdapter(PhpArrayAdapter $phpArrayAdapter, array $values): array
     {
         // make sure we don't cache null values
         $values = array_filter($values, function ($val) { return null !== $val; });
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ConfigBuilderCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ConfigBuilderCacheWarmer.php
index ed20bbcb648d7..c0d96c5ea7b74 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ConfigBuilderCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ConfigBuilderCacheWarmer.php
@@ -42,7 +42,7 @@ public function __construct(KernelInterface $kernel, LoggerInterface $logger = n
      *
      * @return string[]
      */
-    public function warmUp(string $cacheDir)
+    public function warmUp(string $cacheDir): array
     {
         $generator = new ConfigBuilderGenerator($cacheDir);
 
@@ -84,7 +84,7 @@ private function dumpExtension(ExtensionInterface $extension, ConfigBuilderGener
     /**
      * {@inheritdoc}
      */
-    public function isOptional()
+    public function isOptional(): bool
     {
         return true;
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/SerializerCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/SerializerCacheWarmer.php
index 0ada0ffc94349..e574cea817596 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/SerializerCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/SerializerCacheWarmer.php
@@ -42,7 +42,7 @@ public function __construct(array $loaders, string $phpArrayFile)
     /**
      * {@inheritdoc}
      */
-    protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter)
+    protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter): bool
     {
         if (!class_exists(CacheClassMetadataFactory::class) || !method_exists(XmlFileLoader::class, 'getMappedClasses') || !method_exists(YamlFileLoader::class, 'getMappedClasses')) {
             return false;
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/TranslationsCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/TranslationsCacheWarmer.php
index 93423753b2e63..e16ef30b536e5 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/TranslationsCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/TranslationsCacheWarmer.php
@@ -38,7 +38,7 @@ public function __construct(ContainerInterface $container)
      *
      * @return string[]
      */
-    public function warmUp(string $cacheDir)
+    public function warmUp(string $cacheDir): array
     {
         if (null === $this->translator) {
             $this->translator = $this->container->get('translator');
@@ -54,7 +54,7 @@ public function warmUp(string $cacheDir)
     /**
      * {@inheritdoc}
      */
-    public function isOptional()
+    public function isOptional(): bool
     {
         return true;
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ValidatorCacheWarmer.php b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ValidatorCacheWarmer.php
index 3c6d582c43206..6b2c558be96e5 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ValidatorCacheWarmer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/CacheWarmer/ValidatorCacheWarmer.php
@@ -42,7 +42,7 @@ public function __construct(ValidatorBuilder $validatorBuilder, string $phpArray
     /**
      * {@inheritdoc}
      */
-    protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter)
+    protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter): bool
     {
         if (!method_exists($this->validatorBuilder, 'getLoaders')) {
             return false;
@@ -71,7 +71,7 @@ protected function doWarmUp(string $cacheDir, ArrayAdapter $arrayAdapter)
     /**
      * @return string[] A list of classes to preload on PHP 7.4+
      */
-    protected function warmUpPhpArrayAdapter(PhpArrayAdapter $phpArrayAdapter, array $values)
+    protected function warmUpPhpArrayAdapter(PhpArrayAdapter $phpArrayAdapter, array $values): array
     {
         // make sure we don't cache null values
         $values = array_filter($values, function ($val) { return null !== $val; });
diff --git a/src/Symfony/Bundle/FrameworkBundle/Command/AbstractConfigCommand.php b/src/Symfony/Bundle/FrameworkBundle/Command/AbstractConfigCommand.php
index 7650e2963ec03..41d3eddd9964e 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Command/AbstractConfigCommand.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Command/AbstractConfigCommand.php
@@ -54,10 +54,7 @@ protected function listBundles(OutputInterface|StyleInterface $output)
         }
     }
 
-    /**
-     * @return ExtensionInterface
-     */
-    protected function findExtension(string $name)
+    protected function findExtension(string $name): ExtensionInterface
     {
         $bundles = $this->initializeBundles();
         $minScore = \INF;
diff --git a/src/Symfony/Bundle/FrameworkBundle/Console/Application.php b/src/Symfony/Bundle/FrameworkBundle/Console/Application.php
index 7fe7bc937d315..42bed36f56445 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Console/Application.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Console/Application.php
@@ -46,10 +46,8 @@ public function __construct(KernelInterface $kernel)
 
     /**
      * Gets the Kernel associated with this Console.
-     *
-     * @return KernelInterface
      */
-    public function getKernel()
+    public function getKernel(): KernelInterface
     {
         return $this->kernel;
     }
@@ -69,7 +67,7 @@ public function reset()
      *
      * @return int 0 if everything went fine, or an error code
      */
-    public function doRun(InputInterface $input, OutputInterface $output)
+    public function doRun(InputInterface $input, OutputInterface $output): int
     {
         $this->registerCommands();
 
@@ -85,7 +83,7 @@ public function doRun(InputInterface $input, OutputInterface $output)
     /**
      * {@inheritdoc}
      */
-    protected function doRunCommand(Command $command, InputInterface $input, OutputInterface $output)
+    protected function doRunCommand(Command $command, InputInterface $input, OutputInterface $output): int
     {
         if (!$command instanceof ListCommand) {
             if ($this->registrationErrors) {
@@ -109,7 +107,7 @@ protected function doRunCommand(Command $command, InputInterface $input, OutputI
     /**
      * {@inheritdoc}
      */
-    public function find(string $name)
+    public function find(string $name): Command
     {
         $this->registerCommands();
 
@@ -119,7 +117,7 @@ public function find(string $name)
     /**
      * {@inheritdoc}
      */
-    public function get(string $name)
+    public function get(string $name): Command
     {
         $this->registerCommands();
 
@@ -135,7 +133,7 @@ public function get(string $name)
     /**
      * {@inheritdoc}
      */
-    public function all(string $namespace = null)
+    public function all(string $namespace = null): array
     {
         $this->registerCommands();
 
@@ -145,12 +143,12 @@ public function all(string $namespace = null)
     /**
      * {@inheritdoc}
      */
-    public function getLongVersion()
+    public function getLongVersion(): string
     {
         return parent::getLongVersion().sprintf(' (env: <comment>%s</>, debug: <comment>%s</>)', $this->kernel->getEnvironment(), $this->kernel->isDebug() ? 'true' : 'false');
     }
 
-    public function add(Command $command)
+    public function add(Command $command): ?Command
     {
         $this->registerCommands();
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/Descriptor.php b/src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/Descriptor.php
index 1e88cddc307f7..fc5f3ef9b131c 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/Descriptor.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/Descriptor.php
@@ -171,10 +171,7 @@ protected function formatParameter(mixed $value): string
         return (string) $value;
     }
 
-    /**
-     * @return mixed
-     */
-    protected function resolveServiceDefinition(ContainerBuilder $builder, string $serviceId)
+    protected function resolveServiceDefinition(ContainerBuilder $builder, string $serviceId): mixed
     {
         if ($builder->hasDefinition($serviceId)) {
             return $builder->getDefinition($serviceId);
diff --git a/src/Symfony/Bundle/FrameworkBundle/Controller/AbstractController.php b/src/Symfony/Bundle/FrameworkBundle/Controller/AbstractController.php
index 1d83b062f144f..d266faf4aa520 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Controller/AbstractController.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Controller/AbstractController.php
@@ -77,7 +77,7 @@ public function setContainer(ContainerInterface $container): ?ContainerInterface
      *
      * @return array|bool|float|int|string|null
      */
-    protected function getParameter(string $name)
+    protected function getParameter(string $name): array|bool|float|int|string|null
     {
         if (!$this->container->has('parameter_bag')) {
             throw new ServiceNotFoundException('parameter_bag.', null, null, [], sprintf('The "%s::getParameter()" method is missing a parameter bag to work properly. Did you forget to register your controller as a service subscriber? This can be fixed either by using autoconfiguration or by manually wiring a "parameter_bag" in the service locator passed to the controller.', static::class));
@@ -399,7 +399,7 @@ protected function getDoctrine(): ManagerRegistry
      *
      * @see TokenInterface::getUser()
      */
-    protected function getUser()
+    protected function getUser(): ?object
     {
         if (!$this->container->has('security.token_storage')) {
             throw new \LogicException('The SecurityBundle is not registered in your application. Try running "composer require symfony/security-bundle".');
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index 82171117ee739..96e7fa6d5e531 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -62,7 +62,7 @@ public function __construct(bool $debug)
      *
      * @return TreeBuilder The tree builder
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('framework');
         $rootNode = $treeBuilder->getRootNode();
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
index 7d2303dc4d9ab..5729cfe9bbf52 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -37,6 +37,7 @@
 use Symfony\Component\Cache\Marshaller\DefaultMarshaller;
 use Symfony\Component\Cache\Marshaller\MarshallerInterface;
 use Symfony\Component\Cache\ResettableInterface;
+use Symfony\Component\Config\Definition\ConfigurationInterface;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\Config\Resource\DirectoryResource;
@@ -585,7 +586,7 @@ public function load(array $configs, ContainerBuilder $container)
     /**
      * {@inheritdoc}
      */
-    public function getConfiguration(array $config, ContainerBuilder $container)
+    public function getConfiguration(array $config, ContainerBuilder $container): ?ConfigurationInterface
     {
         return new Configuration($container->getParameter('kernel.debug'));
     }
@@ -2583,12 +2584,12 @@ private function resolveTrustedHeaders(array $headers): int
     /**
      * {@inheritdoc}
      */
-    public function getXsdValidationBasePath()
+    public function getXsdValidationBasePath(): string|false
     {
         return \dirname(__DIR__).'/Resources/config/schema';
     }
 
-    public function getNamespace()
+    public function getNamespace(): string
     {
         return 'http://symfony.com/schema/dic/symfony';
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/HttpCache/HttpCache.php b/src/Symfony/Bundle/FrameworkBundle/HttpCache/HttpCache.php
index 5028cadc818a0..eda4928749c0e 100644
--- a/src/Symfony/Bundle/FrameworkBundle/HttpCache/HttpCache.php
+++ b/src/Symfony/Bundle/FrameworkBundle/HttpCache/HttpCache.php
@@ -65,7 +65,7 @@ public function __construct(KernelInterface $kernel, string|StoreInterface $cach
     /**
      * {@inheritdoc}
      */
-    protected function forward(Request $request, bool $catch = false, Response $entry = null)
+    protected function forward(Request $request, bool $catch = false, Response $entry = null): Response
     {
         $this->getKernel()->boot();
         $this->getKernel()->getContainer()->set('cache', $this);
@@ -78,7 +78,7 @@ protected function forward(Request $request, bool $catch = false, Response $entr
      *
      * @return array An array of options
      */
-    protected function getOptions()
+    protected function getOptions(): array
     {
         return [];
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/KernelBrowser.php b/src/Symfony/Bundle/FrameworkBundle/KernelBrowser.php
index 7be3c17bb6d34..9fd548729cf23 100644
--- a/src/Symfony/Bundle/FrameworkBundle/KernelBrowser.php
+++ b/src/Symfony/Bundle/FrameworkBundle/KernelBrowser.php
@@ -44,10 +44,8 @@ public function __construct(KernelInterface $kernel, array $server = [], History
 
     /**
      * Returns the container.
-     *
-     * @return ContainerInterface
      */
-    public function getContainer()
+    public function getContainer(): ContainerInterface
     {
         $container = $this->kernel->getContainer();
 
@@ -56,10 +54,8 @@ public function getContainer()
 
     /**
      * Returns the kernel.
-     *
-     * @return KernelInterface
      */
-    public function getKernel()
+    public function getKernel(): KernelInterface
     {
         return $this->kernel;
     }
@@ -69,7 +65,7 @@ public function getKernel()
      *
      * @return HttpProfile|false|null
      */
-    public function getProfile()
+    public function getProfile(): HttpProfile|false|null
     {
         if (null === $this->response || !$this->getContainer()->has('profiler')) {
             return false;
@@ -146,10 +142,8 @@ public function loginUser(object $user, string $firewallContext = 'main'): self
      * {@inheritdoc}
      *
      * @param Request $request
-     *
-     * @return Response
      */
-    protected function doRequest(object $request)
+    protected function doRequest(object $request): Response
     {
         // avoid shutting down the Kernel if no request has been performed yet
         // WebTestCase::createClient() boots the Kernel but do not handle a request
@@ -173,10 +167,8 @@ protected function doRequest(object $request)
      * {@inheritdoc}
      *
      * @param Request $request
-     *
-     * @return Response
      */
-    protected function doRequestInProcess(object $request)
+    protected function doRequestInProcess(object $request): Response
     {
         $response = parent::doRequestInProcess($request);
 
@@ -194,10 +186,8 @@ protected function doRequestInProcess(object $request)
      * client and override this method.
      *
      * @param Request $request
-     *
-     * @return string
      */
-    protected function getScript(object $request)
+    protected function getScript(object $request): string
     {
         $kernel = var_export(serialize($this->kernel), true);
         $request = var_export(serialize($request), true);
diff --git a/src/Symfony/Bundle/FrameworkBundle/Routing/AnnotatedRouteControllerLoader.php b/src/Symfony/Bundle/FrameworkBundle/Routing/AnnotatedRouteControllerLoader.php
index 511e87058b802..7e6fa732090eb 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Routing/AnnotatedRouteControllerLoader.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Routing/AnnotatedRouteControllerLoader.php
@@ -36,10 +36,8 @@ protected function configureRoute(Route $route, \ReflectionClass $class, \Reflec
 
     /**
      * Makes the default route name more sane by removing common keywords.
-     *
-     * @return string
      */
-    protected function getDefaultRouteName(\ReflectionClass $class, \ReflectionMethod $method)
+    protected function getDefaultRouteName(\ReflectionClass $class, \ReflectionMethod $method): string
     {
         $name = preg_replace('/(bundle|controller)_/', '_', parent::getDefaultRouteName($class, $method));
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php b/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php
index d7900a2e23d59..bfbf787d2d09c 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php
@@ -62,7 +62,7 @@ public function __construct(ContainerInterface $container, mixed $resource, arra
     /**
      * {@inheritdoc}
      */
-    public function getRouteCollection()
+    public function getRouteCollection(): RouteCollection
     {
         if (null === $this->collection) {
             $this->collection = $this->container->get('routing.loader')->load($this->resource, $this->options['resource_type']);
@@ -88,7 +88,7 @@ public function getRouteCollection()
      *
      * @return string[] A list of classes to preload on PHP 7.4+
      */
-    public function warmUp(string $cacheDir)
+    public function warmUp(string $cacheDir): array
     {
         $currentDir = $this->getOption('cache_dir');
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php b/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php
index 6ff70d85060d7..37e86f23c5b23 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php
@@ -57,7 +57,7 @@ protected function tearDown(): void
      * @throws \RuntimeException
      * @throws \LogicException
      */
-    protected static function getKernelClass()
+    protected static function getKernelClass(): string
     {
         if (!isset($_SERVER['KERNEL_CLASS']) && !isset($_ENV['KERNEL_CLASS'])) {
             throw new \LogicException(sprintf('You must set the KERNEL_CLASS environment variable to the fully-qualified class name of your Kernel in phpunit.xml / phpunit.xml.dist or override the "%1$s::createKernel()" or "%1$s::getKernelClass()" method.', static::class));
@@ -72,10 +72,8 @@ protected static function getKernelClass()
 
     /**
      * Boots the Kernel for this test.
-     *
-     * @return KernelInterface
      */
-    protected static function bootKernel(array $options = [])
+    protected static function bootKernel(array $options = []): KernelInterface
     {
         static::ensureKernelShutdown();
 
@@ -117,10 +115,8 @@ protected static function getContainer(): ContainerInterface
      *
      *  * environment
      *  * debug
-     *
-     * @return KernelInterface
      */
-    protected static function createKernel(array $options = [])
+    protected static function createKernel(array $options = []): KernelInterface
     {
         if (null === static::$class) {
             static::$class = static::getKernelClass();
diff --git a/src/Symfony/Bundle/FrameworkBundle/Test/TestBrowserToken.php b/src/Symfony/Bundle/FrameworkBundle/Test/TestBrowserToken.php
index 7580743f6d5cb..6d3c99039b0d8 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Test/TestBrowserToken.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Test/TestBrowserToken.php
@@ -39,7 +39,7 @@ public function getFirewallName(): string
         return $this->firewallName;
     }
 
-    public function getCredentials()
+    public function getCredentials(): mixed
     {
         return null;
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/Test/TestContainer.php b/src/Symfony/Bundle/FrameworkBundle/Test/TestContainer.php
index 7ccb549973901..04f5c9a2b05fa 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Test/TestContainer.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Test/TestContainer.php
@@ -66,7 +66,7 @@ public function getParameterBag(): ParameterBagInterface
      *
      * @return array|bool|float|int|string|null
      */
-    public function getParameter(string $name)
+    public function getParameter(string $name): array|bool|float|int|string|null
     {
         return $this->getPublicContainer()->getParameter($name);
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/Test/WebTestCase.php b/src/Symfony/Bundle/FrameworkBundle/Test/WebTestCase.php
index e1bceae331b32..1f7f0802d3ce1 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Test/WebTestCase.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Test/WebTestCase.php
@@ -34,10 +34,8 @@ protected function tearDown(): void
      *
      * @param array $options An array of options to pass to the createKernel method
      * @param array $server  An array of server parameters
-     *
-     * @return KernelBrowser
      */
-    protected static function createClient(array $options = [], array $server = [])
+    protected static function createClient(array $options = [], array $server = []): KernelBrowser
     {
         if (static::$booted) {
             throw new \LogicException(sprintf('Booting the kernel before calling "%s()" is not supported, the kernel should only be booted once.', __METHOD__));
diff --git a/src/Symfony/Bundle/FrameworkBundle/Translation/Translator.php b/src/Symfony/Bundle/FrameworkBundle/Translation/Translator.php
index 9d7db40406b09..4b7736032e543 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Translation/Translator.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Translation/Translator.php
@@ -96,7 +96,7 @@ public function __construct(ContainerInterface $container, MessageFormatterInter
      *
      * @return string[]
      */
-    public function warmUp(string $cacheDir)
+    public function warmUp(string $cacheDir): array
     {
         // skip warmUp when translator doesn't use cache
         if (null === $this->options['cache_dir']) {
diff --git a/src/Symfony/Bundle/TwigBundle/CacheWarmer/TemplateCacheWarmer.php b/src/Symfony/Bundle/TwigBundle/CacheWarmer/TemplateCacheWarmer.php
index 65f0ae5f067d0..81ef0c63de4bc 100644
--- a/src/Symfony/Bundle/TwigBundle/CacheWarmer/TemplateCacheWarmer.php
+++ b/src/Symfony/Bundle/TwigBundle/CacheWarmer/TemplateCacheWarmer.php
@@ -40,7 +40,7 @@ public function __construct(ContainerInterface $container, iterable $iterator)
      *
      * @return string[] A list of template files to preload on PHP 7.4+
      */
-    public function warmUp(string $cacheDir)
+    public function warmUp(string $cacheDir): array
     {
         if (null === $this->twig) {
             $this->twig = $this->container->get('twig');
@@ -73,7 +73,7 @@ public function warmUp(string $cacheDir)
     /**
      * {@inheritdoc}
      */
-    public function isOptional()
+    public function isOptional(): bool
     {
         return true;
     }
diff --git a/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
index c7826cd5ff73b..d8a67f3aba938 100644
--- a/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
@@ -28,7 +28,7 @@ class Configuration implements ConfigurationInterface
      *
      * @return TreeBuilder The tree builder
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('twig');
         $rootNode = $treeBuilder->getRootNode();
diff --git a/src/Symfony/Bundle/TwigBundle/DependencyInjection/TwigExtension.php b/src/Symfony/Bundle/TwigBundle/DependencyInjection/TwigExtension.php
index f3c8dc2ce9cca..2fb47d3746aef 100644
--- a/src/Symfony/Bundle/TwigBundle/DependencyInjection/TwigExtension.php
+++ b/src/Symfony/Bundle/TwigBundle/DependencyInjection/TwigExtension.php
@@ -183,12 +183,12 @@ private function normalizeBundleName(string $name): string
     /**
      * {@inheritdoc}
      */
-    public function getXsdValidationBasePath()
+    public function getXsdValidationBasePath(): string|false
     {
         return __DIR__.'/../Resources/config/schema';
     }
 
-    public function getNamespace()
+    public function getNamespace(): string
     {
         return 'http://symfony.com/schema/dic/twig';
     }
diff --git a/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php
index f0ac3571278aa..4233706aa2c62 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php
@@ -29,7 +29,7 @@ class Configuration implements ConfigurationInterface
      *
      * @return TreeBuilder The tree builder
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('web_profiler');
 
diff --git a/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/WebProfilerExtension.php b/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/WebProfilerExtension.php
index 0bb949c095a36..d460cf1462035 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/WebProfilerExtension.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/WebProfilerExtension.php
@@ -60,12 +60,12 @@ public function load(array $configs, ContainerBuilder $container)
     /**
      * {@inheritdoc}
      */
-    public function getXsdValidationBasePath()
+    public function getXsdValidationBasePath(): string|false
     {
         return __DIR__.'/../Resources/config/schema';
     }
 
-    public function getNamespace()
+    public function getNamespace(): string
     {
         return 'http://symfony.com/schema/dic/webprofiler';
     }