diff -ruN a/Argument/BoundArgument.php b/Argument/BoundArgument.php
--- a/Argument/BoundArgument.php	2026-07-15 12:28:17
+++ b/Argument/BoundArgument.php	2026-07-15 12:28:17
@@ -28,7 +28,7 @@
     private int $type;
     private ?string $file;
 
-    public function __construct(mixed $value, bool $trackUsage = true, int $type = 0, string $file = null)
+    public function __construct(mixed $value, bool $trackUsage = true, int $type = 0, ?string $file = null)
     {
         $this->value = $value;
         if ($trackUsage) {
diff -ruN a/Argument/ServiceLocator.php b/Argument/ServiceLocator.php
--- a/Argument/ServiceLocator.php	2026-07-15 12:28:17
+++ b/Argument/ServiceLocator.php	2026-07-15 12:28:17
@@ -24,7 +24,7 @@
     private array $serviceMap;
     private ?array $serviceTypes;
 
-    public function __construct(\Closure $factory, array $serviceMap, array $serviceTypes = null)
+    public function __construct(\Closure $factory, array $serviceMap, ?array $serviceTypes = null)
     {
         $this->factory = $factory;
         $this->serviceMap = $serviceMap;
diff -ruN a/Argument/TaggedIteratorArgument.php b/Argument/TaggedIteratorArgument.php
--- a/Argument/TaggedIteratorArgument.php	2026-07-15 12:28:17
+++ b/Argument/TaggedIteratorArgument.php	2026-07-15 12:28:17
@@ -31,7 +31,7 @@
      * @param bool        $needsIndexes          Whether indexes are required and should be generated when computing the map
      * @param string|null $defaultPriorityMethod The static method that should be called to get each service's priority when their tag doesn't define the "priority" attribute
      */
-    public function __construct(string $tag, string $indexAttribute = null, string $defaultIndexMethod = null, bool $needsIndexes = false, string $defaultPriorityMethod = null)
+    public function __construct(string $tag, ?string $indexAttribute = null, ?string $defaultIndexMethod = null, bool $needsIndexes = false, ?string $defaultPriorityMethod = null)
     {
         parent::__construct([]);
 
diff -ruN a/Attribute/AutoconfigureTag.php b/Attribute/AutoconfigureTag.php
--- a/Attribute/AutoconfigureTag.php	2026-07-15 12:28:17
+++ b/Attribute/AutoconfigureTag.php	2026-07-15 12:28:17
@@ -19,7 +19,7 @@
 #[\Attribute(\Attribute::TARGET_CLASS | \Attribute::IS_REPEATABLE)]
 class AutoconfigureTag extends Autoconfigure
 {
-    public function __construct(string $name = null, array $attributes = [])
+    public function __construct(?string $name = null, array $attributes = [])
     {
         parent::__construct(
             tags: [
diff -ruN a/Compiler/CheckTypeDeclarationsPass.php b/Compiler/CheckTypeDeclarationsPass.php
--- a/Compiler/CheckTypeDeclarationsPass.php	2026-07-15 12:28:17
+++ b/Compiler/CheckTypeDeclarationsPass.php	2026-07-15 12:28:17
@@ -158,7 +158,7 @@
     /**
      * @throws InvalidParameterTypeException When a parameter is not compatible with the declared type
      */
-    private function checkType(Definition $checkedDefinition, mixed $value, \ReflectionParameter $parameter, ?string $envPlaceholderUniquePrefix, \ReflectionType $reflectionType = null): void
+    private function checkType(Definition $checkedDefinition, mixed $value, \ReflectionParameter $parameter, ?string $envPlaceholderUniquePrefix, ?\ReflectionType $reflectionType = null): void
     {
         $reflectionType = $reflectionType ?? $parameter->getType();
 
diff -ruN a/Compiler/InlineServiceDefinitionsPass.php b/Compiler/InlineServiceDefinitionsPass.php
--- a/Compiler/InlineServiceDefinitionsPass.php	2026-07-15 12:28:17
+++ b/Compiler/InlineServiceDefinitionsPass.php	2026-07-15 12:28:17
@@ -32,7 +32,7 @@
     private array $notInlinableIds = [];
     private $graph = null;
 
-    public function __construct(AnalyzeServiceReferencesPass $analyzingPass = null)
+    public function __construct(?AnalyzeServiceReferencesPass $analyzingPass = null)
     {
         $this->analyzingPass = $analyzingPass;
     }
diff -ruN a/Compiler/MergeExtensionConfigurationPass.php b/Compiler/MergeExtensionConfigurationPass.php
--- a/Compiler/MergeExtensionConfigurationPass.php	2026-07-15 12:28:17
+++ b/Compiler/MergeExtensionConfigurationPass.php	2026-07-15 12:28:17
@@ -153,7 +153,7 @@
 {
     private string $extensionClass;
 
-    public function __construct(ExtensionInterface $extension, ParameterBagInterface $parameterBag = null)
+    public function __construct(ExtensionInterface $extension, ?ParameterBagInterface $parameterBag = null)
     {
         parent::__construct($parameterBag);
 
@@ -187,7 +187,7 @@
     /**
      * {@inheritdoc}
      */
-    public function resolveEnvPlaceholders(mixed $value, string|bool $format = null, array &$usedEnvs = null): mixed
+    public function resolveEnvPlaceholders(mixed $value, string|bool|null $format = null, ?array &$usedEnvs = null): mixed
     {
         if (true !== $format || !\is_string($value)) {
             return parent::resolveEnvPlaceholders($value, $format, $usedEnvs);
diff -ruN a/Compiler/ServiceLocatorTagPass.php b/Compiler/ServiceLocatorTagPass.php
--- a/Compiler/ServiceLocatorTagPass.php	2026-07-15 12:28:17
+++ b/Compiler/ServiceLocatorTagPass.php	2026-07-15 12:28:17
@@ -104,7 +104,7 @@
     /**
      * @param Reference[] $refMap
      */
-    public static function register(ContainerBuilder $container, array $refMap, string $callerId = null): Reference
+    public static function register(ContainerBuilder $container, array $refMap, ?string $callerId = null): Reference
     {
         foreach ($refMap as $id => $ref) {
             if (!$ref instanceof Reference) {
diff -ruN a/Compiler/ServiceReferenceGraph.php b/Compiler/ServiceReferenceGraph.php
--- a/Compiler/ServiceReferenceGraph.php	2026-07-15 12:28:17
+++ b/Compiler/ServiceReferenceGraph.php	2026-07-15 12:28:17
@@ -74,7 +74,7 @@
     /**
      * Connects 2 nodes together in the Graph.
      */
-    public function connect(?string $sourceId, mixed $sourceValue, ?string $destId, mixed $destValue = null, Reference $reference = null, bool $lazy = false, bool $weak = false, bool $byConstructor = false)
+    public function connect(?string $sourceId, mixed $sourceValue, ?string $destId, mixed $destValue = null, ?Reference $reference = null, bool $lazy = false, bool $weak = false, bool $byConstructor = false)
     {
         if (null === $sourceId || null === $destId) {
             return;
diff -ruN a/Container.php b/Container.php
--- a/Container.php	2026-07-15 12:28:17
+++ b/Container.php	2026-07-15 12:28:17
@@ -62,7 +62,7 @@
     private bool $compiled = false;
     private \Closure $getEnv;
 
-    public function __construct(ParameterBagInterface $parameterBag = null)
+    public function __construct(?ParameterBagInterface $parameterBag = null)
     {
         $this->parameterBag = $parameterBag ?? new EnvPlaceholderParameterBag();
     }
diff -ruN a/ContainerAwareInterface.php b/ContainerAwareInterface.php
--- a/ContainerAwareInterface.php	2026-07-15 12:28:17
+++ b/ContainerAwareInterface.php	2026-07-15 12:28:17
@@ -21,5 +21,5 @@
     /**
      * Sets the container.
      */
-    public function setContainer(ContainerInterface $container = null);
+    public function setContainer(?ContainerInterface $container = null);
 }
diff -ruN a/ContainerAwareTrait.php b/ContainerAwareTrait.php
--- a/ContainerAwareTrait.php	2026-07-15 12:28:17
+++ b/ContainerAwareTrait.php	2026-07-15 12:28:17
@@ -23,7 +23,7 @@
      */
     protected $container;
 
-    public function setContainer(ContainerInterface $container = null)
+    public function setContainer(?ContainerInterface $container = null)
     {
         $this->container = $container;
     }
diff -ruN a/ContainerBuilder.php b/ContainerBuilder.php
--- a/ContainerBuilder.php	2026-07-15 12:28:17
+++ b/ContainerBuilder.php	2026-07-15 12:28:17
@@ -147,7 +147,7 @@
         'mixed' => true,
     ];
 
-    public function __construct(ParameterBagInterface $parameterBag = null)
+    public function __construct(?ParameterBagInterface $parameterBag = null)
     {
         parent::__construct($parameterBag);
 
@@ -416,7 +416,7 @@
      * @throws BadMethodCallException When this ContainerBuilder is compiled
      * @throws \LogicException        if the extension is not registered
      */
-    public function loadFromExtension(string $extension, array $values = null): static
+    public function loadFromExtension(string $extension, ?array $values = null): static
     {
         if ($this->isCompiled()) {
             throw new BadMethodCallException('Cannot load from an extension on a compiled container.');
@@ -512,7 +512,7 @@
         return $this->doGet($id, $invalidBehavior);
     }
 
-    private function doGet(string $id, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, array &$inlineServices = null, bool $isConstructorArgument = false): mixed
+    private function doGet(string $id, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, ?array &$inlineServices = null, bool $isConstructorArgument = false): mixed
     {
         if (isset($inlineServices[$id])) {
             return $inlineServices[$id];
@@ -845,7 +845,7 @@
      * This methods allows for simple registration of service definition
      * with a fluid interface.
      */
-    public function register(string $id, string $class = null): Definition
+    public function register(string $id, ?string $class = null): Definition
     {
         return $this->setDefinition($id, new Definition($class));
     }
@@ -856,7 +856,7 @@
      * This method implements a shortcut for using setDefinition() with
      * an autowired definition.
      */
-    public function autowire(string $id, string $class = null): Definition
+    public function autowire(string $id, ?string $class = null): Definition
     {
         return $this->setDefinition($id, (new Definition($class))->setAutowired(true));
     }
@@ -970,7 +970,7 @@
      * @throws RuntimeException         When the service is a synthetic service
      * @throws InvalidArgumentException When configure callable is not callable
      */
-    private function createService(Definition $definition, array &$inlineServices, bool $isConstructorArgument = false, string $id = null, bool $tryProxy = true): mixed
+    private function createService(Definition $definition, array &$inlineServices, bool $isConstructorArgument = false, ?string $id = null, bool $tryProxy = true): mixed
     {
         if (null === $id && isset($inlineServices[$h = spl_object_hash($definition)])) {
             return $inlineServices[$h];
@@ -1282,7 +1282,7 @@
      * "$fooBar"-named arguments with $type as type-hint. Such arguments will
      * receive the service $id when autowiring is used.
      */
-    public function registerAliasForArgument(string $id, string $type, string $name = null): Alias
+    public function registerAliasForArgument(string $id, string $type, ?string $name = null): Alias
     {
         $name = (new Target($name ?? $id))->name;
 
@@ -1321,7 +1321,7 @@
      *
      * @return mixed The value with env parameters resolved if a string or an array is passed
      */
-    public function resolveEnvPlaceholders(mixed $value, string|bool $format = null, array &$usedEnvs = null): mixed
+    public function resolveEnvPlaceholders(mixed $value, string|bool|null $format = null, ?array &$usedEnvs = null): mixed
     {
         if (null === $format) {
             $format = '%%env(%s)%%';
diff -ruN a/Definition.php b/Definition.php
--- a/Definition.php	2026-07-15 12:28:17
+++ b/Definition.php	2026-07-15 12:28:17
@@ -61,7 +61,7 @@
      */
     public ?int $decorationOnInvalid = null;
 
-    public function __construct(string $class = null, array $arguments = [])
+    public function __construct(?string $class = null, array $arguments = [])
     {
         if (null !== $class) {
             $this->setClass($class);
@@ -133,7 +133,7 @@
      *
      * @throws InvalidArgumentException in case the decorated service id and the new decorated service id are equals
      */
-    public function setDecoratedService(?string $id, string $renamedId = null, int $priority = 0, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE): static
+    public function setDecoratedService(?string $id, ?string $renamedId = null, int $priority = 0, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE): static
     {
         if ($renamedId && $id === $renamedId) {
             throw new InvalidArgumentException(sprintf('The decorated service inner name for "%s" must be different than the service name itself.', $id));
diff -ruN a/Dumper/PhpDumper.php b/Dumper/PhpDumper.php
--- a/Dumper/PhpDumper.php	2026-07-15 12:28:17
+++ b/Dumper/PhpDumper.php	2026-07-15 12:28:17
@@ -1014,7 +1014,7 @@
         return $code;
     }
 
-    private function addInlineService(string $id, Definition $definition, Definition $inlineDef = null, bool $forConstructor = true): string
+    private function addInlineService(string $id, Definition $definition, ?Definition $inlineDef = null, bool $forConstructor = true): string
     {
         $code = '';
 
@@ -1071,7 +1071,7 @@
         return $code;
     }
 
-    private function addServices(array &$services = null): string
+    private function addServices(?array &$services = null): string
     {
         $publicServices = $privateServices = '';
         $definitions = $this->container->getDefinitions();
@@ -1113,7 +1113,7 @@
         }
     }
 
-    private function addNewInstance(Definition $definition, string $return = '', string $id = null): string
+    private function addNewInstance(Definition $definition, string $return = '', ?string $id = null): string
     {
         $tail = $return ? ";\n" : '';
 
@@ -1671,7 +1671,7 @@
         return implode(' && ', $conditions);
     }
 
-    private function getDefinitionsFromArguments(array $arguments, \SplObjectStorage $definitions = null, array &$calls = [], bool $byConstructor = null): \SplObjectStorage
+    private function getDefinitionsFromArguments(array $arguments, ?\SplObjectStorage $definitions = null, array &$calls = [], ?bool $byConstructor = null): \SplObjectStorage
     {
         if (null === $definitions) {
             $definitions = new \SplObjectStorage();
@@ -1902,7 +1902,7 @@
         return sprintf('$this->getParameter(%s)', $this->doExport($name));
     }
 
-    private function getServiceCall(string $id, Reference $reference = null): string
+    private function getServiceCall(string $id, ?Reference $reference = null): string
     {
         while ($this->container->hasAlias($id)) {
             $id = (string) $this->container->getAlias($id);
diff -ruN a/Dumper/YamlDumper.php b/Dumper/YamlDumper.php
--- a/Dumper/YamlDumper.php	2026-07-15 12:28:17
+++ b/Dumper/YamlDumper.php	2026-07-15 12:28:17
@@ -307,7 +307,7 @@
         return $value;
     }
 
-    private function getServiceCall(string $id, Reference $reference = null): string
+    private function getServiceCall(string $id, ?Reference $reference = null): string
     {
         if (null !== $reference) {
             switch ($reference->getInvalidBehavior()) {
diff -ruN a/EnvVarProcessor.php b/EnvVarProcessor.php
--- a/EnvVarProcessor.php	2026-07-15 12:28:17
+++ b/EnvVarProcessor.php	2026-07-15 12:28:17
@@ -27,7 +27,7 @@
     /**
      * @param EnvVarLoaderInterface[] $loaders
      */
-    public function __construct(ContainerInterface $container, \Traversable $loaders = null)
+    public function __construct(ContainerInterface $container, ?\Traversable $loaders = null)
     {
         $this->container = $container;
         $this->loaders = $loaders ?? new \ArrayIterator();
diff -ruN a/Exception/AutowiringFailedException.php b/Exception/AutowiringFailedException.php
--- a/Exception/AutowiringFailedException.php	2026-07-15 12:28:17
+++ b/Exception/AutowiringFailedException.php	2026-07-15 12:28:17
@@ -19,7 +19,7 @@
     private string $serviceId;
     private ?\Closure $messageCallback = null;
 
-    public function __construct(string $serviceId, string|\Closure $message = '', int $code = 0, \Throwable $previous = null)
+    public function __construct(string $serviceId, string|\Closure $message = '', int $code = 0, ?\Throwable $previous = null)
     {
         $this->serviceId = $serviceId;
 
diff -ruN a/Exception/EnvParameterException.php b/Exception/EnvParameterException.php
--- a/Exception/EnvParameterException.php	2026-07-15 12:28:17
+++ b/Exception/EnvParameterException.php	2026-07-15 12:28:17
@@ -18,7 +18,7 @@
  */
 class EnvParameterException extends InvalidArgumentException
 {
-    public function __construct(array $envs, \Throwable $previous = null, string $message = 'Incompatible use of dynamic environment variables "%s" found in parameters.')
+    public function __construct(array $envs, ?\Throwable $previous = null, string $message = 'Incompatible use of dynamic environment variables "%s" found in parameters.')
     {
         parent::__construct(sprintf($message, implode('", "', $envs)), 0, $previous);
     }
diff -ruN a/Exception/ParameterCircularReferenceException.php b/Exception/ParameterCircularReferenceException.php
--- a/Exception/ParameterCircularReferenceException.php	2026-07-15 12:28:17
+++ b/Exception/ParameterCircularReferenceException.php	2026-07-15 12:28:17
@@ -20,7 +20,7 @@
 {
     private array $parameters;
 
-    public function __construct(array $parameters, \Throwable $previous = null)
+    public function __construct(array $parameters, ?\Throwable $previous = null)
     {
         parent::__construct(sprintf('Circular reference detected for parameter "%s" ("%s" > "%s").', $parameters[0], implode('" > "', $parameters), $parameters[0]), 0, $previous);
 
diff -ruN a/Exception/ParameterNotFoundException.php b/Exception/ParameterNotFoundException.php
--- a/Exception/ParameterNotFoundException.php	2026-07-15 12:28:17
+++ b/Exception/ParameterNotFoundException.php	2026-07-15 12:28:17
@@ -34,7 +34,7 @@
      * @param string[]        $alternatives         Some parameter name alternatives
      * @param string|null     $nonNestedAlternative The alternative parameter name when the user expected dot notation for nested parameters
      */
-    public function __construct(string $key, string $sourceId = null, string $sourceKey = null, \Throwable $previous = null, array $alternatives = [], string $nonNestedAlternative = null)
+    public function __construct(string $key, ?string $sourceId = null, ?string $sourceKey = null, ?\Throwable $previous = null, array $alternatives = [], ?string $nonNestedAlternative = null)
     {
         $this->key = $key;
         $this->sourceId = $sourceId;
diff -ruN a/Exception/ServiceCircularReferenceException.php b/Exception/ServiceCircularReferenceException.php
--- a/Exception/ServiceCircularReferenceException.php	2026-07-15 12:28:17
+++ b/Exception/ServiceCircularReferenceException.php	2026-07-15 12:28:17
@@ -21,7 +21,7 @@
     private string $serviceId;
     private array $path;
 
-    public function __construct(string $serviceId, array $path, \Throwable $previous = null)
+    public function __construct(string $serviceId, array $path, ?\Throwable $previous = null)
     {
         parent::__construct(sprintf('Circular reference detected for service "%s", path: "%s".', $serviceId, implode(' -> ', $path)), 0, $previous);
 
diff -ruN a/Exception/ServiceNotFoundException.php b/Exception/ServiceNotFoundException.php
--- a/Exception/ServiceNotFoundException.php	2026-07-15 12:28:17
+++ b/Exception/ServiceNotFoundException.php	2026-07-15 12:28:17
@@ -24,7 +24,7 @@
     private ?string $sourceId;
     private array $alternatives;
 
-    public function __construct(string $id, string $sourceId = null, \Throwable $previous = null, array $alternatives = [], string $msg = null)
+    public function __construct(string $id, ?string $sourceId = null, ?\Throwable $previous = null, array $alternatives = [], ?string $msg = null)
     {
         if (null !== $msg) {
             // no-op
diff -ruN a/ExpressionLanguage.php b/ExpressionLanguage.php
--- a/ExpressionLanguage.php	2026-07-15 12:28:17
+++ b/ExpressionLanguage.php	2026-07-15 12:28:17
@@ -30,7 +30,7 @@
     /**
      * {@inheritdoc}
      */
-    public function __construct(CacheItemPoolInterface $cache = null, array $providers = [], callable $serviceCompiler = null)
+    public function __construct(?CacheItemPoolInterface $cache = null, array $providers = [], ?callable $serviceCompiler = null)
     {
         // prepend the default provider to let users override it easily
         array_unshift($providers, new ExpressionLanguageProvider($serviceCompiler));
diff -ruN a/ExpressionLanguageProvider.php b/ExpressionLanguageProvider.php
--- a/ExpressionLanguageProvider.php	2026-07-15 12:28:17
+++ b/ExpressionLanguageProvider.php	2026-07-15 12:28:17
@@ -26,7 +26,7 @@
 {
     private ?\Closure $serviceCompiler;
 
-    public function __construct(callable $serviceCompiler = null)
+    public function __construct(?callable $serviceCompiler = null)
     {
         $this->serviceCompiler = null !== $serviceCompiler && !$serviceCompiler instanceof \Closure ? \Closure::fromCallable($serviceCompiler) : $serviceCompiler;
     }
diff -ruN a/LazyProxy/ProxyHelper.php b/LazyProxy/ProxyHelper.php
--- a/LazyProxy/ProxyHelper.php	2026-07-15 12:28:17
+++ b/LazyProxy/ProxyHelper.php	2026-07-15 12:28:17
@@ -21,7 +21,7 @@
     /**
      * @return string|null The FQCN or builtin name of the type hint, or null when the type hint references an invalid self|parent context
      */
-    public static function getTypeHint(\ReflectionFunctionAbstract $r, \ReflectionParameter $p = null, bool $noBuiltin = false): ?string
+    public static function getTypeHint(\ReflectionFunctionAbstract $r, ?\ReflectionParameter $p = null, bool $noBuiltin = false): ?string
     {
         if ($p instanceof \ReflectionParameter) {
             $type = $p->getType();
diff -ruN a/Loader/ClosureLoader.php b/Loader/ClosureLoader.php
--- a/Loader/ClosureLoader.php	2026-07-15 12:28:17
+++ b/Loader/ClosureLoader.php	2026-07-15 12:28:17
@@ -25,7 +25,7 @@
 {
     private $container;
 
-    public function __construct(ContainerBuilder $container, string $env = null)
+    public function __construct(ContainerBuilder $container, ?string $env = null)
     {
         $this->container = $container;
         parent::__construct($env);
@@ -34,7 +34,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $resource, string $type = null): mixed
+    public function load(mixed $resource, ?string $type = null): mixed
     {
         return $resource($this->container, $this->env);
     }
@@ -42,7 +42,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         return $resource instanceof \Closure;
     }
diff -ruN a/Loader/Configurator/AbstractServiceConfigurator.php b/Loader/Configurator/AbstractServiceConfigurator.php
--- a/Loader/Configurator/AbstractServiceConfigurator.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/AbstractServiceConfigurator.php	2026-07-15 12:28:17
@@ -20,7 +20,7 @@
     protected $id;
     private array $defaultTags = [];
 
-    public function __construct(ServicesConfigurator $parent, Definition $definition, string $id = null, array $defaultTags = [])
+    public function __construct(ServicesConfigurator $parent, Definition $definition, ?string $id = null, array $defaultTags = [])
     {
         $this->parent = $parent;
         $this->definition = $definition;
@@ -42,7 +42,7 @@
     /**
      * Registers a service.
      */
-    final public function set(?string $id, string $class = null): ServiceConfigurator
+    final public function set(?string $id, ?string $class = null): ServiceConfigurator
     {
         $this->__destruct();
 
@@ -106,7 +106,7 @@
     /**
      * Registers a service.
      */
-    final public function __invoke(string $id, string $class = null): ServiceConfigurator
+    final public function __invoke(string $id, ?string $class = null): ServiceConfigurator
     {
         $this->__destruct();
 
diff -ruN a/Loader/Configurator/ContainerConfigurator.php b/Loader/Configurator/ContainerConfigurator.php
--- a/Loader/Configurator/ContainerConfigurator.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/ContainerConfigurator.php	2026-07-15 12:28:17
@@ -38,7 +38,7 @@
     private int $anonymousCount = 0;
     private ?string $env;
 
-    public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof, string $path, string $file, string $env = null)
+    public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof, string $path, string $file, ?string $env = null)
     {
         $this->container = $container;
         $this->loader = $loader;
@@ -58,7 +58,7 @@
         $this->container->loadFromExtension($namespace, static::processValue($config));
     }
 
-    final public function import(string $resource, string $type = null, bool|string $ignoreErrors = false)
+    final public function import(string $resource, ?string $type = null, bool|string $ignoreErrors = false)
     {
         $this->loader->setCurrentDir(\dirname($this->path));
         $this->loader->import($resource, $type, $ignoreErrors, $this->file);
@@ -111,7 +111,7 @@
 /**
  * Creates an inline service.
  */
-function inline_service(string $class = null): InlineServiceConfigurator
+function inline_service(?string $class = null): InlineServiceConfigurator
 {
     return new InlineServiceConfigurator(new Definition($class));
 }
@@ -139,7 +139,7 @@
 /**
  * Creates a lazy iterator by tag name.
  */
-function tagged_iterator(string $tag, string $indexAttribute = null, string $defaultIndexMethod = null, string $defaultPriorityMethod = null): TaggedIteratorArgument
+function tagged_iterator(string $tag, ?string $indexAttribute = null, ?string $defaultIndexMethod = null, ?string $defaultPriorityMethod = null): TaggedIteratorArgument
 {
     return new TaggedIteratorArgument($tag, $indexAttribute, $defaultIndexMethod, false, $defaultPriorityMethod);
 }
@@ -147,7 +147,7 @@
 /**
  * Creates a service locator by tag name.
  */
-function tagged_locator(string $tag, string $indexAttribute = null, string $defaultIndexMethod = null, string $defaultPriorityMethod = null): ServiceLocatorArgument
+function tagged_locator(string $tag, ?string $indexAttribute = null, ?string $defaultIndexMethod = null, ?string $defaultPriorityMethod = null): ServiceLocatorArgument
 {
     return new ServiceLocatorArgument(new TaggedIteratorArgument($tag, $indexAttribute, $defaultIndexMethod, true, $defaultPriorityMethod));
 }
diff -ruN a/Loader/Configurator/DefaultsConfigurator.php b/Loader/Configurator/DefaultsConfigurator.php
--- a/Loader/Configurator/DefaultsConfigurator.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/DefaultsConfigurator.php	2026-07-15 12:28:17
@@ -28,7 +28,7 @@
 
     private ?string $path;
 
-    public function __construct(ServicesConfigurator $parent, Definition $definition, string $path = null)
+    public function __construct(ServicesConfigurator $parent, Definition $definition, ?string $path = null)
     {
         parent::__construct($parent, $definition, null, []);
 
diff -ruN a/Loader/Configurator/InstanceofConfigurator.php b/Loader/Configurator/InstanceofConfigurator.php
--- a/Loader/Configurator/InstanceofConfigurator.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/InstanceofConfigurator.php	2026-07-15 12:28:17
@@ -32,7 +32,7 @@
 
     private ?string $path;
 
-    public function __construct(ServicesConfigurator $parent, Definition $definition, string $id, string $path = null)
+    public function __construct(ServicesConfigurator $parent, Definition $definition, string $id, ?string $path = null)
     {
         parent::__construct($parent, $definition, $id, []);
 
diff -ruN a/Loader/Configurator/ServiceConfigurator.php b/Loader/Configurator/ServiceConfigurator.php
--- a/Loader/Configurator/ServiceConfigurator.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/ServiceConfigurator.php	2026-07-15 12:28:17
@@ -47,7 +47,7 @@
     private ?string $path;
     private bool $destructed = false;
 
-    public function __construct(ContainerBuilder $container, array $instanceof, bool $allowParent, ServicesConfigurator $parent, Definition $definition, ?string $id, array $defaultTags, string $path = null)
+    public function __construct(ContainerBuilder $container, array $instanceof, bool $allowParent, ServicesConfigurator $parent, Definition $definition, ?string $id, array $defaultTags, ?string $path = null)
     {
         $this->container = $container;
         $this->instanceof = $instanceof;
diff -ruN a/Loader/Configurator/ServicesConfigurator.php b/Loader/Configurator/ServicesConfigurator.php
--- a/Loader/Configurator/ServicesConfigurator.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/ServicesConfigurator.php	2026-07-15 12:28:17
@@ -34,7 +34,7 @@
     private string $anonymousHash;
     private int $anonymousCount;
 
-    public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof, string $path = null, int &$anonymousCount = 0)
+    public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof, ?string $path = null, int &$anonymousCount = 0)
     {
         $this->defaults = new Definition();
         $this->container = $container;
@@ -70,7 +70,7 @@
      * @param string|null $id    The service id, or null to create an anonymous service
      * @param string|null $class The class of the service, or null when $id is also the class name
      */
-    final public function set(?string $id, string $class = null): ServiceConfigurator
+    final public function set(?string $id, ?string $class = null): ServiceConfigurator
     {
         $defaults = $this->defaults;
         $definition = new Definition();
@@ -180,7 +180,7 @@
     /**
      * Registers a service.
      */
-    final public function __invoke(string $id, string $class = null): ServiceConfigurator
+    final public function __invoke(string $id, ?string $class = null): ServiceConfigurator
     {
         return $this->set($id, $class);
     }
diff -ruN a/Loader/Configurator/Traits/DecorateTrait.php b/Loader/Configurator/Traits/DecorateTrait.php
--- a/Loader/Configurator/Traits/DecorateTrait.php	2026-07-15 12:28:17
+++ b/Loader/Configurator/Traits/DecorateTrait.php	2026-07-15 12:28:17
@@ -25,7 +25,7 @@
      *
      * @throws InvalidArgumentException in case the decorated service id and the new decorated service id are equals
      */
-    final public function decorate(?string $id, string $renamedId = null, int $priority = 0, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE): static
+    final public function decorate(?string $id, ?string $renamedId = null, int $priority = 0, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE): static
     {
         $this->definition->setDecoratedService($id, $renamedId, $priority, $invalidBehavior);
 
diff -ruN a/Loader/DirectoryLoader.php b/Loader/DirectoryLoader.php
--- a/Loader/DirectoryLoader.php	2026-07-15 12:28:17
+++ b/Loader/DirectoryLoader.php	2026-07-15 12:28:17
@@ -21,7 +21,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $file, string $type = null): mixed
+    public function load(mixed $file, ?string $type = null): mixed
     {
         $file = rtrim($file, '/');
         $path = $this->locator->locate($file);
@@ -45,7 +45,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         if ('directory' === $type) {
             return true;
diff -ruN a/Loader/FileLoader.php b/Loader/FileLoader.php
--- a/Loader/FileLoader.php	2026-07-15 12:28:17
+++ b/Loader/FileLoader.php	2026-07-15 12:28:17
@@ -40,7 +40,7 @@
     protected $singlyImplemented = [];
     protected $autoRegisterAliasesForSinglyImplementedInterfaces = true;
 
-    public function __construct(ContainerBuilder $container, FileLocatorInterface $locator, string $env = null)
+    public function __construct(ContainerBuilder $container, FileLocatorInterface $locator, ?string $env = null)
     {
         $this->container = $container;
 
@@ -52,7 +52,7 @@
      *
      * @param bool|string $ignoreErrors Whether errors should be ignored; pass "not_found" to ignore only when the loaded resource is not found
      */
-    public function import(mixed $resource, string $type = null, bool|string $ignoreErrors = false, string $sourceResource = null, $exclude = null): mixed
+    public function import(mixed $resource, ?string $type = null, bool|string $ignoreErrors = false, ?string $sourceResource = null, $exclude = null): mixed
     {
         $args = \func_get_args();
 
@@ -91,7 +91,7 @@
      * @param string               $resource  The directory to look for classes, glob-patterns allowed
      * @param string|string[]|null $exclude   A globbed path of files to exclude or an array of globbed paths of files to exclude
      */
-    public function registerClasses(Definition $prototype, string $namespace, string $resource, string|array $exclude = null)
+    public function registerClasses(Definition $prototype, string $namespace, string $resource, string|array|null $exclude = null)
     {
         if (!str_ends_with($namespace, '\\')) {
             throw new InvalidArgumentException(sprintf('Namespace prefix must end with a "\\": "%s".', $namespace));
diff -ruN a/Loader/GlobFileLoader.php b/Loader/GlobFileLoader.php
--- a/Loader/GlobFileLoader.php	2026-07-15 12:28:17
+++ b/Loader/GlobFileLoader.php	2026-07-15 12:28:17
@@ -21,7 +21,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $resource, string $type = null): mixed
+    public function load(mixed $resource, ?string $type = null): mixed
     {
         foreach ($this->glob($resource, false, $globResource) as $path => $info) {
             $this->import($path);
@@ -35,7 +35,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         return 'glob' === $type;
     }
diff -ruN a/Loader/IniFileLoader.php b/Loader/IniFileLoader.php
--- a/Loader/IniFileLoader.php	2026-07-15 12:28:17
+++ b/Loader/IniFileLoader.php	2026-07-15 12:28:17
@@ -24,7 +24,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $resource, string $type = null): mixed
+    public function load(mixed $resource, ?string $type = null): mixed
     {
         $path = $this->locator->locate($resource);
 
@@ -57,7 +57,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         if (!\is_string($resource)) {
             return false;
diff -ruN a/Loader/PhpFileLoader.php b/Loader/PhpFileLoader.php
--- a/Loader/PhpFileLoader.php	2026-07-15 12:28:17
+++ b/Loader/PhpFileLoader.php	2026-07-15 12:28:17
@@ -36,7 +36,7 @@
     protected $autoRegisterAliasesForSinglyImplementedInterfaces = false;
     private $generator;
 
-    public function __construct(ContainerBuilder $container, FileLocatorInterface $locator, string $env = null, ConfigBuilderGeneratorInterface $generator = null)
+    public function __construct(ContainerBuilder $container, FileLocatorInterface $locator, ?string $env = null, ?ConfigBuilderGeneratorInterface $generator = null)
     {
         parent::__construct($container, $locator, $env);
         $this->generator = $generator;
@@ -45,7 +45,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $resource, string $type = null): mixed
+    public function load(mixed $resource, ?string $type = null): mixed
     {
         // the container and loader variables are exposed to the included file below
         $container = $this->container;
@@ -77,7 +77,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         if (!\is_string($resource)) {
             return false;
diff -ruN a/Loader/XmlFileLoader.php b/Loader/XmlFileLoader.php
--- a/Loader/XmlFileLoader.php	2026-07-15 12:28:17
+++ b/Loader/XmlFileLoader.php	2026-07-15 12:28:17
@@ -43,7 +43,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $resource, string $type = null): mixed
+    public function load(mixed $resource, ?string $type = null): mixed
     {
         $path = $this->locator->locate($resource);
 
@@ -70,7 +70,7 @@
         return null;
     }
 
-    private function loadXml(\DOMDocument $xml, string $path, \DOMNode $root = null): void
+    private function loadXml(\DOMDocument $xml, string $path, ?\DOMNode $root = null): void
     {
         $defaults = $this->getServiceDefaults($xml, $path, $root);
 
@@ -98,7 +98,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         if (!\is_string($resource)) {
             return false;
@@ -111,14 +111,14 @@
         return 'xml' === $type;
     }
 
-    private function parseParameters(\DOMDocument $xml, string $file, \DOMNode $root = null)
+    private function parseParameters(\DOMDocument $xml, string $file, ?\DOMNode $root = null)
     {
         if ($parameters = $this->getChildren($root ?? $xml->documentElement, 'parameters')) {
             $this->container->getParameterBag()->add($this->getArgumentsAsPhp($parameters[0], 'parameter', $file));
         }
     }
 
-    private function parseImports(\DOMDocument $xml, string $file, \DOMNode $root = null)
+    private function parseImports(\DOMDocument $xml, string $file, ?\DOMNode $root = null)
     {
         $xpath = new \DOMXPath($xml);
         $xpath->registerNamespace('container', self::NS);
@@ -134,7 +134,7 @@
         }
     }
 
-    private function parseDefinitions(\DOMDocument $xml, string $file, Definition $defaults, \DOMNode $root = null)
+    private function parseDefinitions(\DOMDocument $xml, string $file, Definition $defaults, ?\DOMNode $root = null)
     {
         $xpath = new \DOMXPath($xml);
         $xpath->registerNamespace('container', self::NS);
@@ -192,7 +192,7 @@
         }
     }
 
-    private function getServiceDefaults(\DOMDocument $xml, string $file, \DOMNode $root = null): Definition
+    private function getServiceDefaults(\DOMDocument $xml, string $file, ?\DOMNode $root = null): Definition
     {
         $xpath = new \DOMXPath($xml);
         $xpath->registerNamespace('container', self::NS);
@@ -415,7 +415,7 @@
     /**
      * Processes anonymous services.
      */
-    private function processAnonymousServices(\DOMDocument $xml, string $file, \DOMNode $root = null)
+    private function processAnonymousServices(\DOMDocument $xml, string $file, ?\DOMNode $root = null)
     {
         $definitions = [];
         $count = 0;
diff -ruN a/Loader/YamlFileLoader.php b/Loader/YamlFileLoader.php
--- a/Loader/YamlFileLoader.php	2026-07-15 12:28:17
+++ b/Loader/YamlFileLoader.php	2026-07-15 12:28:17
@@ -116,7 +116,7 @@
     /**
      * {@inheritdoc}
      */
-    public function load(mixed $resource, string $type = null): mixed
+    public function load(mixed $resource, ?string $type = null): mixed
     {
         $path = $this->locator->locate($resource);
 
@@ -183,7 +183,7 @@
     /**
      * {@inheritdoc}
      */
-    public function supports(mixed $resource, string $type = null): bool
+    public function supports(mixed $resource, ?string $type = null): bool
     {
         if (!\is_string($resource)) {
             return false;
diff -ruN a/ServiceLocator.php b/ServiceLocator.php
--- a/ServiceLocator.php	2026-07-15 12:28:17
+++ b/ServiceLocator.php	2026-07-15 12:28:17
@@ -130,7 +130,7 @@
         return new ServiceCircularReferenceException($id, $path);
     }
 
-    private function formatAlternatives(array $alternatives = null, string $separator = 'and'): string
+    private function formatAlternatives(?array $alternatives = null, string $separator = 'and'): string
     {
         $format = '"%s"%s';
         if (null === $alternatives) {
diff -ruN a/TypedReference.php b/TypedReference.php
--- a/TypedReference.php	2026-07-15 12:28:17
+++ b/TypedReference.php	2026-07-15 12:28:17
@@ -27,7 +27,7 @@
      * @param int         $invalidBehavior The behavior when the service does not exist
      * @param string|null $name            The name of the argument targeting the service
      */
-    public function __construct(string $id, string $type, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, string $name = null)
+    public function __construct(string $id, string $type, int $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, ?string $name = null)
     {
         $this->name = $type === $id ? $name : null;
         parent::__construct($id, $invalidBehavior);