diff --git a/BinaryFileResponse.php b/BinaryFileResponse.php
index ca18c92f1..41c3166d8 100644
--- a/BinaryFileResponse.php
+++ b/BinaryFileResponse.php
@@ -45,7 +45,7 @@ class BinaryFileResponse extends Response
      * @param bool                $autoEtag           Whether the ETag header should be automatically set
      * @param bool                $autoLastModified   Whether the Last-Modified header should be automatically set
      */
-    public function __construct(\SplFileInfo|string $file, int $status = 200, array $headers = [], bool $public = true, string $contentDisposition = null, bool $autoEtag = false, bool $autoLastModified = true)
+    public function __construct(\SplFileInfo|string $file, int $status = 200, array $headers = [], bool $public = true, ?string $contentDisposition = null, bool $autoEtag = false, bool $autoLastModified = true)
     {
         parent::__construct(null, $status, $headers);
 
@@ -63,7 +63,7 @@ public function __construct(\SplFileInfo|string $file, int $status = 200, array
      *
      * @throws FileException
      */
-    public function setFile(\SplFileInfo|string $file, string $contentDisposition = null, bool $autoEtag = false, bool $autoLastModified = true): static
+    public function setFile(\SplFileInfo|string $file, ?string $contentDisposition = null, bool $autoEtag = false, bool $autoLastModified = true): static
     {
         if (!$file instanceof File) {
             if ($file instanceof \SplFileInfo) {
diff --git a/Cookie.php b/Cookie.php
index 706f5ca25..4a3b73608 100644
--- a/Cookie.php
+++ b/Cookie.php
@@ -77,7 +77,7 @@ public static function fromString(string $cookie, bool $decode = false): static
      * @param self::SAMESITE_*|''|null $sameSite
      * @param bool                     $partitioned
      */
-    public static function create(string $name, string $value = null, int|string|\DateTimeInterface $expire = 0, ?string $path = '/', string $domain = null, bool $secure = null, bool $httpOnly = true, bool $raw = false, ?string $sameSite = self::SAMESITE_LAX /* , bool $partitioned = false */): self
+    public static function create(string $name, ?string $value = null, int|string|\DateTimeInterface $expire = 0, ?string $path = '/', ?string $domain = null, ?bool $secure = null, bool $httpOnly = true, bool $raw = false, ?string $sameSite = self::SAMESITE_LAX /* , bool $partitioned = false */): self
     {
         $partitioned = 9 < \func_num_args() ? func_get_arg(9) : false;
 
@@ -97,7 +97,7 @@ public static function create(string $name, string $value = null, int|string|\Da
      *
      * @throws \InvalidArgumentException
      */
-    public function __construct(string $name, string $value = null, int|string|\DateTimeInterface $expire = 0, ?string $path = '/', string $domain = null, bool $secure = null, bool $httpOnly = true, bool $raw = false, ?string $sameSite = self::SAMESITE_LAX, bool $partitioned = false)
+    public function __construct(string $name, ?string $value = null, int|string|\DateTimeInterface $expire = 0, ?string $path = '/', ?string $domain = null, ?bool $secure = null, bool $httpOnly = true, bool $raw = false, ?string $sameSite = self::SAMESITE_LAX, bool $partitioned = false)
     {
         // from PHP source code
         if ($raw && false !== strpbrk($name, self::RESERVED_CHARS_LIST)) {
diff --git a/Exception/SessionNotFoundException.php b/Exception/SessionNotFoundException.php
index 94b0cb69a..80a21bf15 100644
--- a/Exception/SessionNotFoundException.php
+++ b/Exception/SessionNotFoundException.php
@@ -20,7 +20,7 @@
  */
 class SessionNotFoundException extends \LogicException implements RequestExceptionInterface
 {
-    public function __construct(string $message = 'There is currently no session available.', int $code = 0, \Throwable $previous = null)
+    public function __construct(string $message = 'There is currently no session available.', int $code = 0, ?\Throwable $previous = null)
     {
         parent::__construct($message, $code, $previous);
     }
diff --git a/File/File.php b/File/File.php
index e8ce4bcf8..34ca5a537 100644
--- a/File/File.php
+++ b/File/File.php
@@ -82,7 +82,7 @@ public function getMimeType(): ?string
      *
      * @throws FileException if the target file could not be created
      */
-    public function move(string $directory, string $name = null): self
+    public function move(string $directory, ?string $name = null): self
     {
         $target = $this->getTargetFile($directory, $name);
 
@@ -112,7 +112,7 @@ public function getContent(): string
         return $content;
     }
 
-    protected function getTargetFile(string $directory, string $name = null): self
+    protected function getTargetFile(string $directory, ?string $name = null): self
     {
         if (!is_dir($directory)) {
             if (false === @mkdir($directory, 0777, true) && !is_dir($directory)) {
diff --git a/File/UploadedFile.php b/File/UploadedFile.php
index e27cf3812..f475d028d 100644
--- a/File/UploadedFile.php
+++ b/File/UploadedFile.php
@@ -60,7 +60,7 @@ class UploadedFile extends File
      * @throws FileException         If file_uploads is disabled
      * @throws FileNotFoundException If the file does not exist
      */
-    public function __construct(string $path, string $originalName, string $mimeType = null, int $error = null, bool $test = false)
+    public function __construct(string $path, string $originalName, ?string $mimeType = null, ?int $error = null, bool $test = false)
     {
         $this->originalName = $this->getName($originalName);
         $this->mimeType = $mimeType ?: 'application/octet-stream';
@@ -158,7 +158,7 @@ public function isValid(): bool
      *
      * @throws FileException if, for any reason, the file could not have been moved
      */
-    public function move(string $directory, string $name = null): File
+    public function move(string $directory, ?string $name = null): File
     {
         if ($this->isValid()) {
             if ($this->test) {
diff --git a/HeaderBag.php b/HeaderBag.php
index 9a3d5549f..4dd777f16 100644
--- a/HeaderBag.php
+++ b/HeaderBag.php
@@ -65,7 +65,7 @@ public function __toString(): string
      *
      * @return ($key is null ? array<string, list<string|null>> : list<string|null>)
      */
-    public function all(string $key = null): array
+    public function all(?string $key = null): array
     {
         if (null !== $key) {
             return $this->headers[strtr($key, self::UPPER, self::LOWER)] ?? [];
@@ -110,7 +110,7 @@ public function add(array $headers)
     /**
      * Returns the first header by name or the default one.
      */
-    public function get(string $key, string $default = null): ?string
+    public function get(string $key, ?string $default = null): ?string
     {
         $headers = $this->all($key);
 
@@ -197,7 +197,7 @@ public function remove(string $key)
      *
      * @throws \RuntimeException When the HTTP header is not parseable
      */
-    public function getDate(string $key, \DateTimeInterface $default = null): ?\DateTimeInterface
+    public function getDate(string $key, ?\DateTimeInterface $default = null): ?\DateTimeInterface
     {
         if (null === $value = $this->get($key)) {
             return null !== $default ? \DateTimeImmutable::createFromInterface($default) : null;
diff --git a/InputBag.php b/InputBag.php
index 7676d9fe7..5acf35fec 100644
--- a/InputBag.php
+++ b/InputBag.php
@@ -84,7 +84,7 @@ public function set(string $key, mixed $value): void
      *
      * @return ?T
      */
-    public function getEnum(string $key, string $class, \BackedEnum $default = null): ?\BackedEnum
+    public function getEnum(string $key, string $class, ?\BackedEnum $default = null): ?\BackedEnum
     {
         try {
             return parent::getEnum($key, $class, $default);
diff --git a/JsonResponse.php b/JsonResponse.php
index 8dd250a36..93c5751f2 100644
--- a/JsonResponse.php
+++ b/JsonResponse.php
@@ -75,7 +75,7 @@ public static function fromJsonString(string $data, int $status = 200, array $he
      *
      * @throws \InvalidArgumentException When the callback name is not valid
      */
-    public function setCallback(string $callback = null): static
+    public function setCallback(?string $callback = null): static
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
diff --git a/ParameterBag.php b/ParameterBag.php
index 0456e474c..48fa4b233 100644
--- a/ParameterBag.php
+++ b/ParameterBag.php
@@ -38,7 +38,7 @@ public function __construct(array $parameters = [])
      *
      * @param string|null $key The name of the parameter to return or null to get them all
      */
-    public function all(string $key = null): array
+    public function all(?string $key = null): array
     {
         if (null === $key) {
             return $this->parameters;
@@ -174,7 +174,7 @@ public function getBoolean(string $key, bool $default = false): bool
      *
      * @return ?T
      */
-    public function getEnum(string $key, string $class, \BackedEnum $default = null): ?\BackedEnum
+    public function getEnum(string $key, string $class, ?\BackedEnum $default = null): ?\BackedEnum
     {
         $value = $this->get($key);
 
diff --git a/Request.php b/Request.php
index 10f3a758f..b482a76dd 100644
--- a/Request.php
+++ b/Request.php
@@ -448,7 +448,7 @@ public static function setFactory(?callable $callable)
      * @param array|null $files      The FILES parameters
      * @param array|null $server     The SERVER parameters
      */
-    public function duplicate(array $query = null, array $request = null, array $attributes = null, array $cookies = null, array $files = null, array $server = null): static
+    public function duplicate(?array $query = null, ?array $request = null, ?array $attributes = null, ?array $cookies = null, ?array $files = null, ?array $server = null): static
     {
         $dup = clone $this;
         if (null !== $query) {
@@ -1606,7 +1606,7 @@ public function getPreferredFormat(?string $default = 'html'): ?string
      *
      * @param string[] $locales An array of ordered available locales
      */
-    public function getPreferredLanguage(array $locales = null): ?string
+    public function getPreferredLanguage(?array $locales = null): ?string
     {
         $preferredLanguages = $this->getLanguages();
 
@@ -2004,7 +2004,7 @@ public function isFromTrustedProxy(): bool
      * getPort(), isSecure(), getHost(), getClientIps(), getBaseUrl() etc. Thus, we try to cache the results for
      * best performance.
      */
-    private function getTrustedValues(int $type, string $ip = null): array
+    private function getTrustedValues(int $type, ?string $ip = null): array
     {
         $cacheKey = $type."\0".((self::$trustedHeaderSet & $type) ? $this->headers->get(self::TRUSTED_HEADERS[$type]) : '');
         $cacheKey .= "\0".$ip."\0".$this->headers->get(self::TRUSTED_HEADERS[self::HEADER_FORWARDED]);
diff --git a/RequestMatcher.php b/RequestMatcher.php
index ac155fa30..b3ca3715d 100644
--- a/RequestMatcher.php
+++ b/RequestMatcher.php
@@ -51,7 +51,7 @@ class RequestMatcher implements RequestMatcherInterface
      * @param string|string[]|null $ips
      * @param string|string[]|null $schemes
      */
-    public function __construct(string $path = null, string $host = null, string|array $methods = null, string|array $ips = null, array $attributes = [], string|array $schemes = null, int $port = null)
+    public function __construct(?string $path = null, ?string $host = null, string|array|null $methods = null, string|array|null $ips = null, array $attributes = [], string|array|null $schemes = null, ?int $port = null)
     {
         $this->matchPath($path);
         $this->matchHost($host);
diff --git a/Response.php b/Response.php
index ef6ece002..d67c8f726 100644
--- a/Response.php
+++ b/Response.php
@@ -497,7 +497,7 @@ public function getProtocolVersion(): string
      *
      * @final
      */
-    public function setStatusCode(int $code, string $text = null): static
+    public function setStatusCode(int $code, ?string $text = null): static
     {
         $this->statusCode = $code;
         if ($this->isInvalid()) {
@@ -762,7 +762,7 @@ public function getExpires(): ?\DateTimeImmutable
      *
      * @final
      */
-    public function setExpires(\DateTimeInterface $date = null): static
+    public function setExpires(?\DateTimeInterface $date = null): static
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
@@ -943,7 +943,7 @@ public function getLastModified(): ?\DateTimeImmutable
      *
      * @final
      */
-    public function setLastModified(\DateTimeInterface $date = null): static
+    public function setLastModified(?\DateTimeInterface $date = null): static
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
@@ -981,7 +981,7 @@ public function getEtag(): ?string
      *
      * @final
      */
-    public function setEtag(string $etag = null, bool $weak = false): static
+    public function setEtag(?string $etag = null, bool $weak = false): static
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
@@ -1284,7 +1284,7 @@ public function isNotFound(): bool
      *
      * @final
      */
-    public function isRedirect(string $location = null): bool
+    public function isRedirect(?string $location = null): bool
     {
         return \in_array($this->statusCode, [201, 301, 302, 303, 307, 308]) && (null === $location ?: $location == $this->headers->get('Location'));
     }
diff --git a/ResponseHeaderBag.php b/ResponseHeaderBag.php
index 10450ca5e..80d267553 100644
--- a/ResponseHeaderBag.php
+++ b/ResponseHeaderBag.php
@@ -86,7 +86,7 @@ public function replace(array $headers = [])
         }
     }
 
-    public function all(string $key = null): array
+    public function all(?string $key = null): array
     {
         $headers = parent::all();
 
@@ -183,7 +183,7 @@ public function setCookie(Cookie $cookie)
      *
      * @return void
      */
-    public function removeCookie(string $name, ?string $path = '/', string $domain = null)
+    public function removeCookie(string $name, ?string $path = '/', ?string $domain = null)
     {
         $path ??= '/';
 
@@ -236,7 +236,7 @@ public function getCookies(string $format = self::COOKIES_FLAT): array
      *
      * @return void
      */
-    public function clearCookie(string $name, ?string $path = '/', string $domain = null, bool $secure = false, bool $httpOnly = true, string $sameSite = null)
+    public function clearCookie(string $name, ?string $path = '/', ?string $domain = null, bool $secure = false, bool $httpOnly = true, ?string $sameSite = null)
     {
         $this->setCookie(new Cookie($name, null, 1, $path, $domain, $secure, $httpOnly, false, $sameSite));
     }
diff --git a/ServerBag.php b/ServerBag.php
index 3e912cb80..09fc38664 100644
--- a/ServerBag.php
+++ b/ServerBag.php
@@ -29,7 +29,7 @@ public function getHeaders(): array
         foreach ($this->parameters as $key => $value) {
             if (str_starts_with($key, 'HTTP_')) {
                 $headers[substr($key, 5)] = $value;
-            } elseif (\in_array($key, ['CONTENT_TYPE', 'CONTENT_LENGTH', 'CONTENT_MD5'], true)) {
+            } elseif (\in_array($key, ['CONTENT_TYPE', 'CONTENT_LENGTH', 'CONTENT_MD5'], true) && '' !== $value) {
                 $headers[$key] = $value;
             }
         }
diff --git a/Session/Session.php b/Session/Session.php
index b45be2f8c..5b6db1754 100644
--- a/Session/Session.php
+++ b/Session/Session.php
@@ -40,7 +40,7 @@ class Session implements FlashBagAwareSessionInterface, \IteratorAggregate, \Cou
     private int $usageIndex = 0;
     private ?\Closure $usageReporter;
 
-    public function __construct(SessionStorageInterface $storage = null, AttributeBagInterface $attributes = null, FlashBagInterface $flashes = null, callable $usageReporter = null)
+    public function __construct(?SessionStorageInterface $storage = null, ?AttributeBagInterface $attributes = null, ?FlashBagInterface $flashes = null, ?callable $usageReporter = null)
     {
         $this->storage = $storage ?? new NativeSessionStorage();
         $this->usageReporter = null === $usageReporter ? null : $usageReporter(...);
@@ -151,14 +151,14 @@ public function isEmpty(): bool
         return true;
     }
 
-    public function invalidate(int $lifetime = null): bool
+    public function invalidate(?int $lifetime = null): bool
     {
         $this->storage->clear();
 
         return $this->migrate(true, $lifetime);
     }
 
-    public function migrate(bool $destroy = false, int $lifetime = null): bool
+    public function migrate(bool $destroy = false, ?int $lifetime = null): bool
     {
         return $this->storage->regenerate($destroy, $lifetime);
     }
diff --git a/Session/SessionFactory.php b/Session/SessionFactory.php
index cdb6af51e..c06ed4b7d 100644
--- a/Session/SessionFactory.php
+++ b/Session/SessionFactory.php
@@ -26,7 +26,7 @@ class SessionFactory implements SessionFactoryInterface
     private SessionStorageFactoryInterface $storageFactory;
     private ?\Closure $usageReporter;
 
-    public function __construct(RequestStack $requestStack, SessionStorageFactoryInterface $storageFactory, callable $usageReporter = null)
+    public function __construct(RequestStack $requestStack, SessionStorageFactoryInterface $storageFactory, ?callable $usageReporter = null)
     {
         $this->requestStack = $requestStack;
         $this->storageFactory = $storageFactory;
diff --git a/Session/SessionInterface.php b/Session/SessionInterface.php
index 534883d2d..07785a6f4 100644
--- a/Session/SessionInterface.php
+++ b/Session/SessionInterface.php
@@ -62,7 +62,7 @@ public function setName(string $name);
      *                           to expire with browser session. Time is in seconds, and is
      *                           not a Unix timestamp.
      */
-    public function invalidate(int $lifetime = null): bool;
+    public function invalidate(?int $lifetime = null): bool;
 
     /**
      * Migrates the current session to a new session id while maintaining all
@@ -74,7 +74,7 @@ public function invalidate(int $lifetime = null): bool;
      *                           to expire with browser session. Time is in seconds, and is
      *                           not a Unix timestamp.
      */
-    public function migrate(bool $destroy = false, int $lifetime = null): bool;
+    public function migrate(bool $destroy = false, ?int $lifetime = null): bool;
 
     /**
      * Force the session to be saved and closed.
diff --git a/Session/Storage/Handler/NativeFileSessionHandler.php b/Session/Storage/Handler/NativeFileSessionHandler.php
index f6e73f9e6..f8c6151a4 100644
--- a/Session/Storage/Handler/NativeFileSessionHandler.php
+++ b/Session/Storage/Handler/NativeFileSessionHandler.php
@@ -28,7 +28,7 @@ class NativeFileSessionHandler extends \SessionHandler
      * @throws \InvalidArgumentException On invalid $savePath
      * @throws \RuntimeException         When failing to create the save directory
      */
-    public function __construct(string $savePath = null)
+    public function __construct(?string $savePath = null)
     {
         $baseDir = $savePath ??= \ini_get('session.save_path');
 
diff --git a/Session/Storage/Handler/PdoSessionHandler.php b/Session/Storage/Handler/PdoSessionHandler.php
index 1e8f9c6c4..9cee76ddf 100644
--- a/Session/Storage/Handler/PdoSessionHandler.php
+++ b/Session/Storage/Handler/PdoSessionHandler.php
@@ -151,7 +151,7 @@ class PdoSessionHandler extends AbstractSessionHandler
      *
      * @throws \InvalidArgumentException When PDO error mode is not PDO::ERRMODE_EXCEPTION
      */
-    public function __construct(#[\SensitiveParameter] \PDO|string $pdoOrDsn = null, #[\SensitiveParameter] array $options = [])
+    public function __construct(#[\SensitiveParameter] \PDO|string|null $pdoOrDsn = null, #[\SensitiveParameter] array $options = [])
     {
         if ($pdoOrDsn instanceof \PDO) {
             if (\PDO::ERRMODE_EXCEPTION !== $pdoOrDsn->getAttribute(\PDO::ATTR_ERRMODE)) {
@@ -181,7 +181,7 @@ public function __construct(#[\SensitiveParameter] \PDO|string $pdoOrDsn = null,
     /**
      * Adds the Table to the Schema if it doesn't exist.
      */
-    public function configureSchema(Schema $schema, \Closure $isSameDatabase = null): void
+    public function configureSchema(Schema $schema, ?\Closure $isSameDatabase = null): void
     {
         if ($schema->hasTable($this->table) || ($isSameDatabase && !$isSameDatabase($this->getConnection()->exec(...)))) {
             return;
diff --git a/Session/Storage/MetadataBag.php b/Session/Storage/MetadataBag.php
index ebe4b748a..5bb4cfbc7 100644
--- a/Session/Storage/MetadataBag.php
+++ b/Session/Storage/MetadataBag.php
@@ -88,7 +88,7 @@ public function getLifetime(): int
      *
      * @return void
      */
-    public function stampNew(int $lifetime = null)
+    public function stampNew(?int $lifetime = null)
     {
         $this->stampCreated($lifetime);
     }
@@ -139,7 +139,7 @@ public function setName(string $name)
         $this->name = $name;
     }
 
-    private function stampCreated(int $lifetime = null): void
+    private function stampCreated(?int $lifetime = null): void
     {
         $timeStamp = time();
         $this->meta[self::CREATED] = $this->meta[self::UPDATED] = $this->lastUsed = $timeStamp;
diff --git a/Session/Storage/MockArraySessionStorage.php b/Session/Storage/MockArraySessionStorage.php
index d30b56d69..5d1802561 100644
--- a/Session/Storage/MockArraySessionStorage.php
+++ b/Session/Storage/MockArraySessionStorage.php
@@ -62,7 +62,7 @@ class MockArraySessionStorage implements SessionStorageInterface
      */
     protected $bags = [];
 
-    public function __construct(string $name = 'MOCKSESSID', MetadataBag $metaBag = null)
+    public function __construct(string $name = 'MOCKSESSID', ?MetadataBag $metaBag = null)
     {
         $this->name = $name;
         $this->setMetadataBag($metaBag);
@@ -91,7 +91,7 @@ public function start(): bool
         return true;
     }
 
-    public function regenerate(bool $destroy = false, int $lifetime = null): bool
+    public function regenerate(bool $destroy = false, ?int $lifetime = null): bool
     {
         if (!$this->started) {
             $this->start();
@@ -192,7 +192,7 @@ public function isStarted(): bool
     /**
      * @return void
      */
-    public function setMetadataBag(MetadataBag $bag = null)
+    public function setMetadataBag(?MetadataBag $bag = null)
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
diff --git a/Session/Storage/MockFileSessionStorage.php b/Session/Storage/MockFileSessionStorage.php
index 95f69f2e1..ef6d9d8f8 100644
--- a/Session/Storage/MockFileSessionStorage.php
+++ b/Session/Storage/MockFileSessionStorage.php
@@ -30,7 +30,7 @@ class MockFileSessionStorage extends MockArraySessionStorage
     /**
      * @param string|null $savePath Path of directory to save session files
      */
-    public function __construct(string $savePath = null, string $name = 'MOCKSESSID', MetadataBag $metaBag = null)
+    public function __construct(?string $savePath = null, string $name = 'MOCKSESSID', ?MetadataBag $metaBag = null)
     {
         $savePath ??= sys_get_temp_dir();
 
@@ -60,7 +60,7 @@ public function start(): bool
         return true;
     }
 
-    public function regenerate(bool $destroy = false, int $lifetime = null): bool
+    public function regenerate(bool $destroy = false, ?int $lifetime = null): bool
     {
         if (!$this->started) {
             $this->start();
diff --git a/Session/Storage/MockFileSessionStorageFactory.php b/Session/Storage/MockFileSessionStorageFactory.php
index 8ecf943dc..6727cf14f 100644
--- a/Session/Storage/MockFileSessionStorageFactory.php
+++ b/Session/Storage/MockFileSessionStorageFactory.php
@@ -28,7 +28,7 @@ class MockFileSessionStorageFactory implements SessionStorageFactoryInterface
     /**
      * @see MockFileSessionStorage constructor.
      */
-    public function __construct(string $savePath = null, string $name = 'MOCKSESSID', MetadataBag $metaBag = null)
+    public function __construct(?string $savePath = null, string $name = 'MOCKSESSID', ?MetadataBag $metaBag = null)
     {
         $this->savePath = $savePath;
         $this->name = $name;
diff --git a/Session/Storage/NativeSessionStorage.php b/Session/Storage/NativeSessionStorage.php
index 7c6b6f929..f63de5740 100644
--- a/Session/Storage/NativeSessionStorage.php
+++ b/Session/Storage/NativeSessionStorage.php
@@ -89,7 +89,7 @@ class NativeSessionStorage implements SessionStorageInterface
      * trans_sid_hosts, $_SERVER['HTTP_HOST']
      * trans_sid_tags, "a=href,area=href,frame=src,form="
      */
-    public function __construct(array $options = [], AbstractProxy|\SessionHandlerInterface $handler = null, MetadataBag $metaBag = null)
+    public function __construct(array $options = [], AbstractProxy|\SessionHandlerInterface|null $handler = null, ?MetadataBag $metaBag = null)
     {
         if (!\extension_loaded('session')) {
             throw new \LogicException('PHP extension "session" is required.');
@@ -204,7 +204,7 @@ public function setName(string $name)
         $this->saveHandler->setName($name);
     }
 
-    public function regenerate(bool $destroy = false, int $lifetime = null): bool
+    public function regenerate(bool $destroy = false, ?int $lifetime = null): bool
     {
         // Cannot regenerate the session ID for non-active sessions.
         if (\PHP_SESSION_ACTIVE !== session_status()) {
@@ -317,7 +317,7 @@ public function getBag(string $name): SessionBagInterface
     /**
      * @return void
      */
-    public function setMetadataBag(MetadataBag $metaBag = null)
+    public function setMetadataBag(?MetadataBag $metaBag = null)
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
@@ -396,7 +396,7 @@ public function setOptions(array $options)
      *
      * @throws \InvalidArgumentException
      */
-    public function setSaveHandler(AbstractProxy|\SessionHandlerInterface $saveHandler = null)
+    public function setSaveHandler(AbstractProxy|\SessionHandlerInterface|null $saveHandler = null)
     {
         if (1 > \func_num_args()) {
             trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
@@ -429,7 +429,7 @@ public function setSaveHandler(AbstractProxy|\SessionHandlerInterface $saveHandl
      *
      * @return void
      */
-    protected function loadSession(array &$session = null)
+    protected function loadSession(?array &$session = null)
     {
         if (null === $session) {
             $session = &$_SESSION;
diff --git a/Session/Storage/NativeSessionStorageFactory.php b/Session/Storage/NativeSessionStorageFactory.php
index 08901284c..6463a4c1b 100644
--- a/Session/Storage/NativeSessionStorageFactory.php
+++ b/Session/Storage/NativeSessionStorageFactory.php
@@ -30,7 +30,7 @@ class NativeSessionStorageFactory implements SessionStorageFactoryInterface
     /**
      * @see NativeSessionStorage constructor.
      */
-    public function __construct(array $options = [], AbstractProxy|\SessionHandlerInterface $handler = null, MetadataBag $metaBag = null, bool $secure = false)
+    public function __construct(array $options = [], AbstractProxy|\SessionHandlerInterface|null $handler = null, ?MetadataBag $metaBag = null, bool $secure = false)
     {
         $this->options = $options;
         $this->handler = $handler;
diff --git a/Session/Storage/PhpBridgeSessionStorage.php b/Session/Storage/PhpBridgeSessionStorage.php
index 28cb3c3d0..4fb26d2a9 100644
--- a/Session/Storage/PhpBridgeSessionStorage.php
+++ b/Session/Storage/PhpBridgeSessionStorage.php
@@ -20,7 +20,7 @@
  */
 class PhpBridgeSessionStorage extends NativeSessionStorage
 {
-    public function __construct(AbstractProxy|\SessionHandlerInterface $handler = null, MetadataBag $metaBag = null)
+    public function __construct(AbstractProxy|\SessionHandlerInterface|null $handler = null, ?MetadataBag $metaBag = null)
     {
         if (!\extension_loaded('session')) {
             throw new \LogicException('PHP extension "session" is required.');
diff --git a/Session/Storage/PhpBridgeSessionStorageFactory.php b/Session/Storage/PhpBridgeSessionStorageFactory.php
index 5cc738024..aa4f800d3 100644
--- a/Session/Storage/PhpBridgeSessionStorageFactory.php
+++ b/Session/Storage/PhpBridgeSessionStorageFactory.php
@@ -26,7 +26,7 @@ class PhpBridgeSessionStorageFactory implements SessionStorageFactoryInterface
     private ?MetadataBag $metaBag;
     private bool $secure;
 
-    public function __construct(AbstractProxy|\SessionHandlerInterface $handler = null, MetadataBag $metaBag = null, bool $secure = false)
+    public function __construct(AbstractProxy|\SessionHandlerInterface|null $handler = null, ?MetadataBag $metaBag = null, bool $secure = false)
     {
         $this->handler = $handler;
         $this->metaBag = $metaBag;
diff --git a/Session/Storage/SessionStorageInterface.php b/Session/Storage/SessionStorageInterface.php
index ed2189e4e..7865135b0 100644
--- a/Session/Storage/SessionStorageInterface.php
+++ b/Session/Storage/SessionStorageInterface.php
@@ -84,7 +84,7 @@ public function setName(string $name);
      *
      * @throws \RuntimeException If an error occurs while regenerating this storage
      */
-    public function regenerate(bool $destroy = false, int $lifetime = null): bool;
+    public function regenerate(bool $destroy = false, ?int $lifetime = null): bool;
 
     /**
      * Force the session to be saved and closed.
diff --git a/StreamedResponse.php b/StreamedResponse.php
index 87be96a11..0ab88e098 100644
--- a/StreamedResponse.php
+++ b/StreamedResponse.php
@@ -33,7 +33,7 @@ class StreamedResponse extends Response
     /**
      * @param int $status The HTTP status code (200 "OK" by default)
      */
-    public function __construct(callable $callback = null, int $status = 200, array $headers = [])
+    public function __construct(?callable $callback = null, int $status = 200, array $headers = [])
     {
         parent::__construct(null, $status, $headers);
 
diff --git a/Test/Constraint/ResponseCookieValueSame.php b/Test/Constraint/ResponseCookieValueSame.php
index 417efc77a..768007b95 100644
--- a/Test/Constraint/ResponseCookieValueSame.php
+++ b/Test/Constraint/ResponseCookieValueSame.php
@@ -22,7 +22,7 @@ final class ResponseCookieValueSame extends Constraint
     private string $path;
     private ?string $domain;
 
-    public function __construct(string $name, string $value, string $path = '/', string $domain = null)
+    public function __construct(string $name, string $value, string $path = '/', ?string $domain = null)
     {
         $this->name = $name;
         $this->value = $value;
diff --git a/Test/Constraint/ResponseHasCookie.php b/Test/Constraint/ResponseHasCookie.php
index 73393d386..8eccea9d1 100644
--- a/Test/Constraint/ResponseHasCookie.php
+++ b/Test/Constraint/ResponseHasCookie.php
@@ -21,7 +21,7 @@ final class ResponseHasCookie extends Constraint
     private string $path;
     private ?string $domain;
 
-    public function __construct(string $name, string $path = '/', string $domain = null)
+    public function __construct(string $name, string $path = '/', ?string $domain = null)
     {
         $this->name = $name;
         $this->path = $path;
diff --git a/Tests/HeaderUtilsTest.php b/Tests/HeaderUtilsTest.php
index befa4aea0..3279b9a53 100644
--- a/Tests/HeaderUtilsTest.php
+++ b/Tests/HeaderUtilsTest.php
@@ -149,7 +149,7 @@ public static function provideMakeDispositionFail()
     /**
      * @dataProvider provideParseQuery
      */
-    public function testParseQuery(string $query, string $expected = null)
+    public function testParseQuery(string $query, ?string $expected = null)
     {
         $this->assertSame($expected ?? $query, http_build_query(HeaderUtils::parseQuery($query), '', '&'));
     }
diff --git a/Tests/ServerBagTest.php b/Tests/ServerBagTest.php
index e26714bc4..3d675c512 100644
--- a/Tests/ServerBagTest.php
+++ b/Tests/ServerBagTest.php
@@ -177,4 +177,20 @@ public function testItDoesNotOverwriteTheAuthorizationHeaderIfItIsAlreadySet()
             'PHP_AUTH_PW' => '',
         ], $bag->getHeaders());
     }
+
+    /**
+     * An HTTP request without content-type and content-length will result in
+     * the variables $_SERVER['CONTENT_TYPE'] and $_SERVER['CONTENT_LENGTH']
+     * containing an empty string in PHP.
+     */
+    public function testRequestWithoutContentTypeAndContentLength()
+    {
+        $bag = new ServerBag([
+            'CONTENT_TYPE' => '',
+            'CONTENT_LENGTH' => '',
+            'HTTP_USER_AGENT' => 'foo',
+        ]);
+
+        $this->assertSame(['USER_AGENT' => 'foo'], $bag->getHeaders());
+    }
 }
diff --git a/Tests/Session/Storage/Handler/PdoSessionHandlerTest.php b/Tests/Session/Storage/Handler/PdoSessionHandlerTest.php
index cd34c72e3..ede4703aa 100644
--- a/Tests/Session/Storage/Handler/PdoSessionHandlerTest.php
+++ b/Tests/Session/Storage/Handler/PdoSessionHandlerTest.php
@@ -408,7 +408,7 @@ class MockPdo extends \PDO
     private ?string $driverName;
     private bool|int $errorMode;
 
-    public function __construct(string $driverName = null, int $errorMode = null)
+    public function __construct(?string $driverName = null, ?int $errorMode = null)
     {
         $this->driverName = $driverName;
         $this->errorMode = null !== $errorMode ?: \PDO::ERRMODE_EXCEPTION;