diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd142c813..bcc45df12 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,10 @@ for a given releases. Unreleased, upcoming changes will be updated here periodic
 
 # 2.x
 
+## [2.12.2](https://github.com/liip/LiipImagineBundle/tree/2.12.2)
+
+- Avoid PHP 8.3 warning with default empty prefix ([simonberger](https://github.com/liip/LiipImagineBundle/pull/1568))
+
 ## [2.12.1](https://github.com/liip/LiipImagineBundle/tree/2.12.1)
 
 - Adjustments to install with Symfony 7 ([mbabker](https://github.com/liip/LiipImagineBundle/pull/1535))
diff --git a/src/Component/Console/Style/ImagineStyle.php b/src/Component/Console/Style/ImagineStyle.php
index 1a3f61c77..d3b24ebe9 100644
--- a/src/Component/Console/Style/ImagineStyle.php
+++ b/src/Component/Console/Style/ImagineStyle.php
@@ -52,14 +52,14 @@ public function newline(int $count = 1): self
         return $this;
     }
 
-    public function status(string $status, string $fg = null): self
+    public function status(string $status, ?string $fg = null): self
     {
         return $this->text(
             sprintf('<fg=%2$s>(</><fg=%2$s;options=bold>%1$s</><fg=%2$s>)</>', $status, $fg ?: 'default')
         );
     }
 
-    public function group(string $item, string $group, string $fg = null): self
+    public function group(string $item, string $group, ?string $fg = null): self
     {
         $this->text(
             sprintf('<fg=%3$s;options=bold>%1$s[</><fg=%3$s>%2$s</><fg=%3$s;options=bold>]</>', $item, $group, $fg ?: 'default')
@@ -68,7 +68,7 @@ public function group(string $item, string $group, string $fg = null): self
         return $this->space();
     }
 
-    public function title(string $title, string $type = null): self
+    public function title(string $title, ?string $type = null): self
     {
         if (!$this->decoration) {
             return $this->plainTitle($title, $type);
@@ -87,7 +87,7 @@ public function critBlock(string $string, array $replacements = []): self
         return $this->largeBlock($this->compileString(strip_tags($string), $replacements), 'ERROR', 'white', 'red', '#');
     }
 
-    private function largeBlock(string $string, string $type, string $fg = null, string $bg = null, string $prefix = null): self
+    private function largeBlock(string $string, string $type, ?string $fg = null, ?string $bg = null, ?string $prefix = null): self
     {
         return $this->block($string, $type, $fg, $bg, $prefix, true);
     }
@@ -97,7 +97,7 @@ private function space(int $count = 1): self
         return $this->text(str_repeat(' ', $count));
     }
 
-    private function plainTitle(string $title, string $type = null): self
+    private function plainTitle(string $title, ?string $type = null): self
     {
         $this->newline();
 
@@ -110,7 +110,7 @@ private function plainTitle(string $title, string $type = null): self
         return $this->newline();
     }
 
-    private function block(string $string, string $type = null, string $fg = null, string $bg = null, string $prefix = null, bool $padding = true): self
+    private function block(string $string, ?string $type = null, ?string $fg = null, ?string $bg = null, ?string $prefix = null, bool $padding = true): self
     {
         if (!$this->decoration) {
             return $this->plainBlock($string, $type);
diff --git a/src/Config/Filter/Argument/Point.php b/src/Config/Filter/Argument/Point.php
index 70dd4c179..ade620b3f 100644
--- a/src/Config/Filter/Argument/Point.php
+++ b/src/Config/Filter/Argument/Point.php
@@ -20,7 +20,7 @@ final class Point
 
     private ?int $y;
 
-    public function __construct(int $x = null, int $y = null)
+    public function __construct(?int $x = null, ?int $y = null)
     {
         $this->x = $x;
         $this->y = $y;
diff --git a/src/Config/Filter/Argument/Size.php b/src/Config/Filter/Argument/Size.php
index 1a93cf599..9f3bea9ac 100644
--- a/src/Config/Filter/Argument/Size.php
+++ b/src/Config/Filter/Argument/Size.php
@@ -24,7 +24,7 @@ final class Size
      * To allow keeping aspect ratio, it is allowed to only specify one of width or height.
      * It is however not allowed to specify neither dimension.
      */
-    public function __construct(int $width = null, int $height = null)
+    public function __construct(?int $width = null, ?int $height = null)
     {
         $this->width = $width;
         $this->height = $height;
diff --git a/src/Config/Filter/Type/Downscale.php b/src/Config/Filter/Type/Downscale.php
index 1aafb77de..0b6211dc1 100644
--- a/src/Config/Filter/Type/Downscale.php
+++ b/src/Config/Filter/Type/Downscale.php
@@ -27,7 +27,7 @@ final class Downscale extends FilterAbstract
     /**
      * @param float|null $by sets the "ratio multiple" which initiates a proportional scale operation computed by multiplying all image sides by this value
      */
-    public function __construct(Size $max = null, float $by = null)
+    public function __construct(?Size $max = null, ?float $by = null)
     {
         $this->max = $max;
         $this->by = $by;
diff --git a/src/Config/Filter/Type/RelativeResize.php b/src/Config/Filter/Type/RelativeResize.php
index d295961c0..51a7d7b5f 100644
--- a/src/Config/Filter/Type/RelativeResize.php
+++ b/src/Config/Filter/Type/RelativeResize.php
@@ -27,10 +27,10 @@ final class RelativeResize extends FilterAbstract
     private ?float $scale;
 
     public function __construct(
-        float $heighten = null,
-        float $widen = null,
-        float $increase = null,
-        float $scale = null
+        ?float $heighten = null,
+        ?float $widen = null,
+        ?float $increase = null,
+        ?float $scale = null
     ) {
         $this->heighten = $heighten;
         $this->widen = $widen;
diff --git a/src/Config/Filter/Type/Scale.php b/src/Config/Filter/Type/Scale.php
index 1d0c7b445..e3d5d5b88 100644
--- a/src/Config/Filter/Type/Scale.php
+++ b/src/Config/Filter/Type/Scale.php
@@ -27,7 +27,7 @@ final class Scale extends FilterAbstract
     /**
      * @param float|null $to proportional scale operation computed by multiplying all image sides by this value
      */
-    public function __construct(Size $dimensions, float $to = null)
+    public function __construct(Size $dimensions, ?float $to = null)
     {
         $this->dimensions = $dimensions;
         $this->to = $to;
diff --git a/src/Config/Filter/Type/Thumbnail.php b/src/Config/Filter/Type/Thumbnail.php
index 8bc8ed2ec..3c12d68cc 100644
--- a/src/Config/Filter/Type/Thumbnail.php
+++ b/src/Config/Filter/Type/Thumbnail.php
@@ -30,9 +30,9 @@ final class Thumbnail extends FilterAbstract
 
     public function __construct(
         Size $size,
-        string $mode = null,
-        bool $allowUpscale = null,
-        string $filter = null
+        ?string $mode = null,
+        ?bool $allowUpscale = null,
+        ?string $filter = null
     ) {
         $this->size = $size;
         $this->mode = $mode;
diff --git a/src/Config/Filter/Type/Upscale.php b/src/Config/Filter/Type/Upscale.php
index ba0e2d26d..b95cb0b81 100644
--- a/src/Config/Filter/Type/Upscale.php
+++ b/src/Config/Filter/Type/Upscale.php
@@ -27,7 +27,7 @@ final class Upscale extends FilterAbstract
     /**
      * @param float|null $by sets the "ratio multiple" which initiates a proportional scale operation computed by multiplying all image sides by this value
      */
-    public function __construct(Size $min, float $by = null)
+    public function __construct(Size $min, ?float $by = null)
     {
         $this->min = $min;
         $this->by = $by;
diff --git a/src/Config/Filter/Type/Watermark.php b/src/Config/Filter/Type/Watermark.php
index 4bae0e33d..5c41156c1 100644
--- a/src/Config/Filter/Type/Watermark.php
+++ b/src/Config/Filter/Type/Watermark.php
@@ -24,7 +24,7 @@ final class Watermark extends FilterAbstract
 
     private ?float $size;
 
-    public function __construct(string $image, string $position, float $size = null)
+    public function __construct(string $image, string $position, ?float $size = null)
     {
         $this->image = $image;
         $this->position = $position;
diff --git a/src/Config/Stack.php b/src/Config/Stack.php
index 06e890671..74b594bdb 100644
--- a/src/Config/Stack.php
+++ b/src/Config/Stack.php
@@ -27,7 +27,7 @@ final class Stack implements StackInterface
      * @param string|null       $dataLoader name of a custom data loader. Default value: filesystem (which means the standard filesystem loader is used).
      * @param FilterInterface[] $filters
      */
-    public function __construct(string $name, string $dataLoader = null, int $quality = null, array $filters = [])
+    public function __construct(string $name, ?string $dataLoader, ?int $quality, array $filters = [])
     {
         $this->name = $name;
         $this->dataLoader = $dataLoader;
diff --git a/src/Controller/ImagineController.php b/src/Controller/ImagineController.php
index 3838c27c5..2e9e5cf32 100644
--- a/src/Controller/ImagineController.php
+++ b/src/Controller/ImagineController.php
@@ -38,7 +38,7 @@ public function __construct(
         FilterService $filterService,
         DataManager $dataManager,
         SignerInterface $signer,
-        ControllerConfig $controllerConfig
+        ?ControllerConfig $controllerConfig
     ) {
         $this->filterService = $filterService;
         $this->dataManager = $dataManager;
@@ -103,7 +103,7 @@ public function filterRuntimeAction(Request $request, string $hash, string $path
         }, $path, $filter, $hash);
     }
 
-    private function createRedirectResponse(\Closure $url, string $path, string $filter, string $hash = null): RedirectResponse
+    private function createRedirectResponse(\Closure $url, string $path, string $filter, ?string $hash = null): RedirectResponse
     {
         try {
             return new RedirectResponse($url(), $this->controllerConfig->getRedirectResponseCode());
diff --git a/src/DependencyInjection/Factory/Loader/AbstractLoaderFactory.php b/src/DependencyInjection/Factory/Loader/AbstractLoaderFactory.php
index 3cf0f188c..515a0111b 100644
--- a/src/DependencyInjection/Factory/Loader/AbstractLoaderFactory.php
+++ b/src/DependencyInjection/Factory/Loader/AbstractLoaderFactory.php
@@ -19,7 +19,7 @@ abstract class AbstractLoaderFactory implements LoaderFactoryInterface
 {
     protected static string $namePrefix = 'liip_imagine.binary.loader';
 
-    final protected function getChildLoaderDefinition(string $name = null): ChildDefinition
+    final protected function getChildLoaderDefinition(?string $name = null): ChildDefinition
     {
         return new ChildDefinition(sprintf('%s.prototype.%s', static::$namePrefix, $name ?: $this->getName()));
     }
diff --git a/src/DependencyInjection/Factory/Resolver/AbstractResolverFactory.php b/src/DependencyInjection/Factory/Resolver/AbstractResolverFactory.php
index c3de07770..bb11d114e 100644
--- a/src/DependencyInjection/Factory/Resolver/AbstractResolverFactory.php
+++ b/src/DependencyInjection/Factory/Resolver/AbstractResolverFactory.php
@@ -17,7 +17,7 @@ abstract class AbstractResolverFactory implements ResolverFactoryInterface
 {
     protected static string $namePrefix = 'liip_imagine.cache.resolver';
 
-    final protected function getChildResolverDefinition(string $name = null): ChildDefinition
+    final protected function getChildResolverDefinition(?string $name = null): ChildDefinition
     {
         return new ChildDefinition(sprintf('%s.prototype.%s', static::$namePrefix, $name ?: $this->getName()));
     }
diff --git a/src/DependencyInjection/Factory/Resolver/AwsS3ResolverFactory.php b/src/DependencyInjection/Factory/Resolver/AwsS3ResolverFactory.php
index 9d62353a2..8279034b2 100644
--- a/src/DependencyInjection/Factory/Resolver/AwsS3ResolverFactory.php
+++ b/src/DependencyInjection/Factory/Resolver/AwsS3ResolverFactory.php
@@ -93,7 +93,7 @@ public function addConfiguration(ArrayNodeDefinition $builder): void
                     ->cannotBeEmpty()
                 ->end()
                 ->scalarNode('cache_prefix')
-                    ->defaultValue(null)
+                    ->defaultValue('')
                 ->end()
                 ->arrayNode('client_config')
                     ->isRequired()
diff --git a/src/DependencyInjection/Factory/Resolver/FlysystemResolverFactory.php b/src/DependencyInjection/Factory/Resolver/FlysystemResolverFactory.php
index 710fd928e..cd3f4c528 100644
--- a/src/DependencyInjection/Factory/Resolver/FlysystemResolverFactory.php
+++ b/src/DependencyInjection/Factory/Resolver/FlysystemResolverFactory.php
@@ -49,7 +49,7 @@ public function addConfiguration(ArrayNodeDefinition $builder): void
                     ->cannotBeEmpty()
                 ->end()
                 ->scalarNode('cache_prefix')
-                    ->defaultValue(null)
+                    ->defaultValue('')
                 ->end()
                 ->scalarNode('root_url')
                     ->isRequired()
diff --git a/src/Events/CacheResolveEvent.php b/src/Events/CacheResolveEvent.php
index 46b9a82de..dcec6ef32 100644
--- a/src/Events/CacheResolveEvent.php
+++ b/src/Events/CacheResolveEvent.php
@@ -33,7 +33,7 @@ class CacheResolveEvent extends Event
     /**
      * Init default event state.
      */
-    public function __construct(string $path, string $filter, string $url = null)
+    public function __construct(string $path, string $filter, ?string $url = null)
     {
         $this->path = $path;
         $this->filter = $filter;
diff --git a/src/Factory/Config/Filter/Argument/PointFactory.php b/src/Factory/Config/Filter/Argument/PointFactory.php
index e412bcc73..d4938c173 100644
--- a/src/Factory/Config/Filter/Argument/PointFactory.php
+++ b/src/Factory/Config/Filter/Argument/PointFactory.php
@@ -21,7 +21,7 @@
  */
 final class PointFactory
 {
-    public function create(int $x = null, int $y = null): Point
+    public function create(?int $x = null, ?int $y = null): Point
     {
         return new Point($x, $y);
     }
diff --git a/src/Factory/Config/Filter/Argument/SizeFactory.php b/src/Factory/Config/Filter/Argument/SizeFactory.php
index 6b2294411..aabe9cdca 100644
--- a/src/Factory/Config/Filter/Argument/SizeFactory.php
+++ b/src/Factory/Config/Filter/Argument/SizeFactory.php
@@ -21,7 +21,7 @@
  */
 final class SizeFactory
 {
-    public function create(int $width = null, int $height = null): Size
+    public function create(?int $width = null, ?int $height = null): Size
     {
         return new Size($width, $height);
     }
diff --git a/src/Factory/Config/StackFactory.php b/src/Factory/Config/StackFactory.php
index 29b5333fd..e5993b93a 100644
--- a/src/Factory/Config/StackFactory.php
+++ b/src/Factory/Config/StackFactory.php
@@ -19,7 +19,7 @@
  */
 final class StackFactory implements StackFactoryInterface
 {
-    public function create(string $name, string $dataLoader = null, int $quality = null, array $filters = []): StackInterface
+    public function create(string $name, ?string $dataLoader, ?int $quality, array $filters = []): StackInterface
     {
         return new Stack($name, $dataLoader, $quality, $filters);
     }
diff --git a/src/Factory/Config/StackFactoryInterface.php b/src/Factory/Config/StackFactoryInterface.php
index a8099cb63..c6f3dd3c7 100644
--- a/src/Factory/Config/StackFactoryInterface.php
+++ b/src/Factory/Config/StackFactoryInterface.php
@@ -19,5 +19,5 @@ interface StackFactoryInterface
     /**
      * @param FilterInterface[] $filters
      */
-    public function create(string $name, string $dataLoader = null, int $quality = null, array $filters = []): StackInterface;
+    public function create(string $name, ?string $dataLoader, ?int $quality, array $filters = []): StackInterface;
 }
diff --git a/src/Imagine/Cache/CacheManager.php b/src/Imagine/Cache/CacheManager.php
index 4a1da10a0..67256c8b9 100644
--- a/src/Imagine/Cache/CacheManager.php
+++ b/src/Imagine/Cache/CacheManager.php
@@ -48,7 +48,7 @@ public function __construct(
         RouterInterface $router,
         SignerInterface $signer,
         EventDispatcherInterface $dispatcher,
-        string $defaultResolver = null,
+        ?string $defaultResolver = null,
         bool $webpGenerate = false
     ) {
         $this->filterConfig = $filterConfig;
@@ -77,7 +77,7 @@ public function addResolver(string $filter, ResolverInterface $resolver): void
      *
      * @param string $path The path where the resolved file is expected
      */
-    public function getBrowserPath(string $path, string $filter, array $runtimeConfig = [], string $resolver = null, int $referenceType = UrlGeneratorInterface::ABSOLUTE_URL): string
+    public function getBrowserPath(string $path, string $filter, array $runtimeConfig = [], ?string $resolver = null, int $referenceType = UrlGeneratorInterface::ABSOLUTE_URL): string
     {
         if (!empty($runtimeConfig)) {
             $rcPath = $this->getRuntimePath($path, $runtimeConfig);
@@ -109,7 +109,7 @@ public function getRuntimePath(string $path, array $runtimeConfig): string
      * @param string $filter        The name of the imagine filter in effect
      * @param int    $referenceType The type of reference to be generated (one of the UrlGenerator constants)
      */
-    public function generateUrl(string $path, string $filter, array $runtimeConfig = [], string $resolver = null, int $referenceType = UrlGeneratorInterface::ABSOLUTE_URL): string
+    public function generateUrl(string $path, string $filter, array $runtimeConfig = [], ?string $resolver = null, int $referenceType = UrlGeneratorInterface::ABSOLUTE_URL): string
     {
         $params = [
             'path' => ltrim($path, '/'),
@@ -135,7 +135,7 @@ public function generateUrl(string $path, string $filter, array $runtimeConfig =
     /**
      * Checks whether the path is already stored within the respective Resolver.
      */
-    public function isStored(string $path, string $filter, string $resolver = null): bool
+    public function isStored(string $path, string $filter, ?string $resolver = null): bool
     {
         return $this->getResolver($filter, $resolver)->isStored($path, $filter);
     }
@@ -147,7 +147,7 @@ public function isStored(string $path, string $filter, string $resolver = null):
      *
      * @return string The url of resolved image
      */
-    public function resolve(string $path, string $filter, string $resolver = null): string
+    public function resolve(string $path, string $filter, ?string $resolver = null): string
     {
         if (false !== mb_strpos($path, '/../') || 0 === mb_strpos($path, '../')) {
             throw new NotFoundHttpException(sprintf("Source image was searched with '%s' outside of the defined root path", $path));
@@ -167,7 +167,7 @@ public function resolve(string $path, string $filter, string $resolver = null):
     /**
      * @see ResolverInterface::store
      */
-    public function store(BinaryInterface $binary, string $path, string $filter, string $resolver = null): void
+    public function store(BinaryInterface $binary, string $path, string $filter, ?string $resolver = null): void
     {
         $this->getResolver($filter, $resolver)->store($binary, $path, $filter);
     }
diff --git a/src/Imagine/Cache/Resolver/AbstractFilesystemResolver.php b/src/Imagine/Cache/Resolver/AbstractFilesystemResolver.php
index 925052b57..52295605b 100644
--- a/src/Imagine/Cache/Resolver/AbstractFilesystemResolver.php
+++ b/src/Imagine/Cache/Resolver/AbstractFilesystemResolver.php
@@ -38,7 +38,7 @@ public function __construct(Filesystem $filesystem)
         $this->filesystem = $filesystem;
     }
 
-    public function setRequest(Request $request = null): void
+    public function setRequest(?Request $request = null): void
     {
         $this->request = $request;
     }
diff --git a/src/Imagine/Cache/Resolver/PsrCacheResolver.php b/src/Imagine/Cache/Resolver/PsrCacheResolver.php
index 320e2a00b..4eb3f5b9e 100644
--- a/src/Imagine/Cache/Resolver/PsrCacheResolver.php
+++ b/src/Imagine/Cache/Resolver/PsrCacheResolver.php
@@ -47,7 +47,7 @@ final class PsrCacheResolver implements ResolverInterface
      * * index_key
      *   The name of the index key being used to save a list of created cache keys regarding one image and filter pairing.
      */
-    public function __construct(CacheItemPoolInterface $cache, ResolverInterface $cacheResolver, array $options = [], OptionsResolver $optionsResolver = null)
+    public function __construct(CacheItemPoolInterface $cache, ResolverInterface $cacheResolver, array $options = [], ?OptionsResolver $optionsResolver = null)
     {
         $this->cache = $cache;
         $this->resolver = $cacheResolver;
diff --git a/src/Imagine/Cache/Signer.php b/src/Imagine/Cache/Signer.php
index 5c3dc5f5a..877f80292 100644
--- a/src/Imagine/Cache/Signer.php
+++ b/src/Imagine/Cache/Signer.php
@@ -20,7 +20,7 @@ public function __construct(string $secret)
         $this->secret = $secret;
     }
 
-    public function sign(string $path, array $runtimeConfig = null): string
+    public function sign(string $path, ?array $runtimeConfig = null): string
     {
         if ($runtimeConfig) {
             array_walk_recursive($runtimeConfig, function (&$value) {
@@ -31,7 +31,7 @@ public function sign(string $path, array $runtimeConfig = null): string
         return mb_substr(preg_replace('/[^a-zA-Z0-9-_]/', '', base64_encode(hash_hmac('sha256', ltrim($path, '/').(null === $runtimeConfig ?: serialize($runtimeConfig)), $this->secret, true))), 0, 8);
     }
 
-    public function check(string $hash, string $path, array $runtimeConfig = null): bool
+    public function check(string $hash, string $path, ?array $runtimeConfig = null): bool
     {
         return $hash === $this->sign($path, $runtimeConfig);
     }
diff --git a/src/Imagine/Cache/SignerInterface.php b/src/Imagine/Cache/SignerInterface.php
index 859373524..69ebaea67 100644
--- a/src/Imagine/Cache/SignerInterface.php
+++ b/src/Imagine/Cache/SignerInterface.php
@@ -16,10 +16,10 @@ interface SignerInterface
     /**
      * Return the hash for path and runtime config.
      */
-    public function sign(string $path, array $runtimeConfig = null): string;
+    public function sign(string $path, ?array $runtimeConfig = null): string;
 
     /**
      * Check hash is correct.
      */
-    public function check(string $hash, string $path, array $runtimeConfig = null): bool;
+    public function check(string $hash, string $path, ?array $runtimeConfig = null): bool;
 }
diff --git a/src/Imagine/Data/DataManager.php b/src/Imagine/Data/DataManager.php
index 39bbd80fc..064b228c8 100644
--- a/src/Imagine/Data/DataManager.php
+++ b/src/Imagine/Data/DataManager.php
@@ -40,8 +40,8 @@ public function __construct(
         MimeTypeGuesserInterface $mimeTypeGuesser,
         MimeTypesInterface $extensionGuesser,
         FilterConfiguration $filterConfig,
-        string $defaultLoader = null,
-        string $globalDefaultImage = null
+        ?string $defaultLoader = null,
+        ?string $globalDefaultImage = null
     ) {
         $this->mimeTypeGuesser = $mimeTypeGuesser;
         $this->filterConfig = $filterConfig;
diff --git a/src/Imagine/Filter/PostProcessor/AbstractPostProcessor.php b/src/Imagine/Filter/PostProcessor/AbstractPostProcessor.php
index 54bdefe3b..7524dfd7e 100644
--- a/src/Imagine/Filter/PostProcessor/AbstractPostProcessor.php
+++ b/src/Imagine/Filter/PostProcessor/AbstractPostProcessor.php
@@ -25,7 +25,7 @@ abstract class AbstractPostProcessor implements PostProcessorInterface
 
     private Filesystem $filesystem;
 
-    public function __construct(string $executablePath, string $temporaryRootPath = null)
+    public function __construct(string $executablePath, ?string $temporaryRootPath = null)
     {
         $this->executablePath = $executablePath;
         $this->temporaryRootPath = $temporaryRootPath;
@@ -70,7 +70,7 @@ protected function isBinaryTypeMatch(BinaryInterface $binary, array $types): boo
         return \in_array($binary->getMimeType(), $types, true);
     }
 
-    protected function writeTemporaryFile(BinaryInterface $binary, array $options = [], string $prefix = null): string
+    protected function writeTemporaryFile(BinaryInterface $binary, array $options = [], ?string $prefix = null): string
     {
         $temporary = $this->acquireTemporaryFilePath($options, $prefix);
 
@@ -83,7 +83,7 @@ protected function writeTemporaryFile(BinaryInterface $binary, array $options =
         return $temporary;
     }
 
-    protected function acquireTemporaryFilePath(array $options, string $prefix = null): string
+    protected function acquireTemporaryFilePath(array $options, ?string $prefix = null): string
     {
         $root = $options['temp_dir'] ?? $this->temporaryRootPath ?: sys_get_temp_dir();
 
diff --git a/src/Imagine/Filter/PostProcessor/CwebpPostProcessor.php b/src/Imagine/Filter/PostProcessor/CwebpPostProcessor.php
index 3ef82c13b..86ae48c7f 100644
--- a/src/Imagine/Filter/PostProcessor/CwebpPostProcessor.php
+++ b/src/Imagine/Filter/PostProcessor/CwebpPostProcessor.php
@@ -95,13 +95,13 @@ class CwebpPostProcessor extends AbstractPostProcessor
      */
     public function __construct(
         string $executablePath = '/usr/bin/cwebp',
-        string $temporaryRootPath = null,
-        int $q = null,
-        int $alphaQ = null,
-        int $m = null,
-        string $alphaFilter = null,
-        int $alphaMethod = null,
-        bool $exact = null,
+        ?string $temporaryRootPath = null,
+        ?int $q = null,
+        ?int $alphaQ = null,
+        ?int $m = null,
+        ?string $alphaFilter = null,
+        ?int $alphaMethod = null,
+        ?bool $exact = null,
         array $metadata = []
     ) {
         parent::__construct($executablePath, $temporaryRootPath);
diff --git a/src/Imagine/Filter/PostProcessor/JpegOptimPostProcessor.php b/src/Imagine/Filter/PostProcessor/JpegOptimPostProcessor.php
index dd8a9ff2b..117f804b9 100644
--- a/src/Imagine/Filter/PostProcessor/JpegOptimPostProcessor.php
+++ b/src/Imagine/Filter/PostProcessor/JpegOptimPostProcessor.php
@@ -40,7 +40,7 @@ class JpegOptimPostProcessor extends AbstractPostProcessor
      * @param bool        $progressive       Force output to be progressive
      * @param string|null $temporaryRootPath Directory where temporary file will be written
      */
-    public function __construct(string $executablePath = '/usr/bin/jpegoptim', bool $strip = true, int $quality = null, bool $progressive = true, string $temporaryRootPath = null)
+    public function __construct(string $executablePath = '/usr/bin/jpegoptim', bool $strip = true, ?int $quality = null, bool $progressive = true, ?string $temporaryRootPath = null)
     {
         parent::__construct($executablePath, $temporaryRootPath);
 
diff --git a/src/Imagine/Filter/PostProcessor/MozJpegPostProcessor.php b/src/Imagine/Filter/PostProcessor/MozJpegPostProcessor.php
index a7f8b225b..ccf7149fe 100644
--- a/src/Imagine/Filter/PostProcessor/MozJpegPostProcessor.php
+++ b/src/Imagine/Filter/PostProcessor/MozJpegPostProcessor.php
@@ -34,7 +34,7 @@ class MozJpegPostProcessor extends AbstractPostProcessor
      * @param string   $executablePath Path to the mozjpeg cjpeg binary
      * @param int|null $quality        Quality factor
      */
-    public function __construct(string $executablePath = '/opt/mozjpeg/bin/cjpeg', int $quality = null)
+    public function __construct(string $executablePath = '/opt/mozjpeg/bin/cjpeg', ?int $quality = null)
     {
         parent::__construct($executablePath);
 
diff --git a/src/Imagine/Filter/PostProcessor/OptiPngPostProcessor.php b/src/Imagine/Filter/PostProcessor/OptiPngPostProcessor.php
index bf3b23c0c..2cf93bac4 100644
--- a/src/Imagine/Filter/PostProcessor/OptiPngPostProcessor.php
+++ b/src/Imagine/Filter/PostProcessor/OptiPngPostProcessor.php
@@ -34,7 +34,7 @@ class OptiPngPostProcessor extends AbstractPostProcessor
      * @param bool        $strip             Strip metadata objects
      * @param string|null $temporaryRootPath Directory where temporary file will be written
      */
-    public function __construct(string $executablePath = '/usr/bin/optipng', int $level = 7, bool $strip = true, string $temporaryRootPath = null)
+    public function __construct(string $executablePath = '/usr/bin/optipng', int $level = 7, bool $strip = true, ?string $temporaryRootPath = null)
     {
         parent::__construct($executablePath, $temporaryRootPath);
 
diff --git a/src/Message/WarmupCache.php b/src/Message/WarmupCache.php
index 5e34ccca0..a9879ee33 100644
--- a/src/Message/WarmupCache.php
+++ b/src/Message/WarmupCache.php
@@ -33,7 +33,7 @@ class WarmupCache
      * @param string[]|null $filters List of filter set names to warm up. If not set, all available filter sets are warmed up
      * @param bool          $force   Whether to recreate existing cached images or only create them when no cache currently exists
      */
-    public function __construct(string $path, array $filters = null, bool $force = false)
+    public function __construct(string $path, ?array $filters = null, bool $force = false)
     {
         $this->path = $path;
         $this->filters = $filters;
diff --git a/src/Model/Binary.php b/src/Model/Binary.php
index 9cb600659..582d92dcf 100644
--- a/src/Model/Binary.php
+++ b/src/Model/Binary.php
@@ -21,7 +21,7 @@ class Binary implements BinaryInterface
 
     protected ?string $format;
 
-    public function __construct(string $content, ?string $mimeType, string $format = null)
+    public function __construct(string $content, ?string $mimeType, ?string $format = null)
     {
         $this->content = $content;
         $this->mimeType = $mimeType;
diff --git a/src/Model/FileBinary.php b/src/Model/FileBinary.php
index dc84b946b..3a2e0d71b 100644
--- a/src/Model/FileBinary.php
+++ b/src/Model/FileBinary.php
@@ -21,7 +21,7 @@ class FileBinary implements FileBinaryInterface
 
     protected ?string $format;
 
-    public function __construct(string $path, ?string $mimeType, string $format = null)
+    public function __construct(string $path, ?string $mimeType, ?string $format = null)
     {
         $this->path = $path;
         $this->mimeType = $mimeType;
diff --git a/src/Service/FilterService.php b/src/Service/FilterService.php
index 515169441..9a0fb1935 100644
--- a/src/Service/FilterService.php
+++ b/src/Service/FilterService.php
@@ -42,7 +42,7 @@ public function __construct(
         CacheManager $cacheManager,
         bool $webpGenerate,
         array $webpOptions,
-        LoggerInterface $logger = null
+        ?LoggerInterface $logger = null
     ) {
         $this->dataManager = $dataManager;
         $this->filterManager = $filterManager;
@@ -78,7 +78,7 @@ public function bustCache(string $path, string $filter): bool
     public function warmUpCache(
         string $path,
         string $filter,
-        string $resolver = null,
+        ?string $resolver = null,
         bool $forced = false
     ): bool {
         $warmedUp = false;
@@ -92,7 +92,7 @@ public function warmUpCache(
         return $warmedUp;
     }
 
-    public function getUrlOfFilteredImage(string $path, string $filter, string $resolver = null, bool $webpSupported = false): string
+    public function getUrlOfFilteredImage(string $path, string $filter, ?string $resolver = null, bool $webpSupported = false): string
     {
         foreach ($this->buildFilterPathContainers($path) as $filterPathContainer) {
             $this->warmUpCacheFilterPathContainer($filterPathContainer, $filter, $resolver);
@@ -105,7 +105,7 @@ public function getUrlOfFilteredImageWithRuntimeFilters(
         string $path,
         string $filter,
         array $runtimeFilters = [],
-        string $resolver = null,
+        ?string $resolver = null,
         bool $webpSupported = false
     ): string {
         $runtimePath = $this->cacheManager->getRuntimePath($path, $runtimeFilters);
@@ -145,7 +145,7 @@ private function buildFilterPathContainers(string $source, string $target = '',
     private function resolveFilterPathContainer(
         FilterPathContainer $filterPathContainer,
         string $filter,
-        string $resolver = null,
+        ?string $resolver = null,
         bool $webpSupported = false
     ): string {
         $path = $filterPathContainer->getTarget();
@@ -165,7 +165,7 @@ private function resolveFilterPathContainer(
     private function warmUpCacheFilterPathContainer(
         FilterPathContainer $filterPathContainer,
         string $filter,
-        string $resolver = null,
+        ?string $resolver = null,
         bool $forced = false
     ): bool {
         if ($forced || !$this->cacheManager->isStored($filterPathContainer->getTarget(), $filter, $resolver)) {
diff --git a/src/Templating/LazyFilterRuntime.php b/src/Templating/LazyFilterRuntime.php
index 794208b40..aec3a1a09 100644
--- a/src/Templating/LazyFilterRuntime.php
+++ b/src/Templating/LazyFilterRuntime.php
@@ -24,7 +24,7 @@ final class LazyFilterRuntime implements RuntimeExtensionInterface
      */
     private ?string $assetVersion;
 
-    public function __construct(CacheManager $cache, string $assetVersion = null)
+    public function __construct(CacheManager $cache, ?string $assetVersion = null)
     {
         $this->cache = $cache;
         $this->assetVersion = $assetVersion;
@@ -33,7 +33,7 @@ public function __construct(CacheManager $cache, string $assetVersion = null)
     /**
      * Gets the browser path for the image and filter to apply.
      */
-    public function filter(string $path, string $filter, array $config = [], string $resolver = null, int $referenceType = UrlGeneratorInterface::ABSOLUTE_URL): string
+    public function filter(string $path, string $filter, array $config = [], ?string $resolver = null, int $referenceType = UrlGeneratorInterface::ABSOLUTE_URL): string
     {
         $path = $this->cleanPath($path);
         $path = $this->cache->getBrowserPath($path, $filter, $config, $resolver, $referenceType);
@@ -46,7 +46,7 @@ public function filter(string $path, string $filter, array $config = [], string
      *
      * This does not check whether the cached image exists or not.
      */
-    public function filterCache(string $path, string $filter, array $config = [], string $resolver = null): string
+    public function filterCache(string $path, string $filter, array $config = [], ?string $resolver = null): string
     {
         $path = $this->cleanPath($path);
         if (\count($config)) {
diff --git a/src/Utility/Framework/SymfonyFramework.php b/src/Utility/Framework/SymfonyFramework.php
index 982bdff66..dc8301c43 100644
--- a/src/Utility/Framework/SymfonyFramework.php
+++ b/src/Utility/Framework/SymfonyFramework.php
@@ -23,17 +23,17 @@ public static function getContainerResolvableRootWebPath(): string
         return sprintf('%%kernel.project_dir%%/%s', self::isKernelLessThan(4) ? 'web' : 'public');
     }
 
-    public static function isKernelGreaterThanOrEqualTo(int $major, int $minor = null, int $patch = null): bool
+    public static function isKernelGreaterThanOrEqualTo(int $major, ?int $minor = null, ?int $patch = null): bool
     {
         return static::kernelVersionCompare('>=', $major, $minor, $patch);
     }
 
-    public static function isKernelLessThan(int $major, int $minor = null, int $patch = null): bool
+    public static function isKernelLessThan(int $major, ?int $minor = null, ?int $patch = null): bool
     {
         return static::kernelVersionCompare('<', $major, $minor, $patch);
     }
 
-    private static function kernelVersionCompare(string $operator, int $major, int $minor = null, int $patch = null): bool
+    private static function kernelVersionCompare(string $operator, int $major, ?int $minor = null, ?int $patch = null): bool
     {
         return version_compare((string) Kernel::VERSION_ID, sprintf("%d%'.02d%'.02d", $major, $minor ?: 0, $patch ?: 0), $operator);
     }
diff --git a/tests/Binary/Loader/ChainLoaderTest.php b/tests/Binary/Loader/ChainLoaderTest.php
index 6a727b59f..8ca738cc8 100644
--- a/tests/Binary/Loader/ChainLoaderTest.php
+++ b/tests/Binary/Loader/ChainLoaderTest.php
@@ -130,7 +130,7 @@ private function getFileSystemLocator(array $paths = []): FileSystemLocator
      * @param string[]           $paths
      * @param FileSystemLoader[] $loaders
      */
-    private function getChainLoader(array $paths = [], array $loaders = null): ChainLoader
+    private function getChainLoader(array $paths = [], ?array $loaders = null): ChainLoader
     {
         if (null === $loaders) {
             $loaders = [
diff --git a/tests/Binary/Loader/FileSystemLoaderTest.php b/tests/Binary/Loader/FileSystemLoaderTest.php
index 6d5a5cd20..b02badd18 100644
--- a/tests/Binary/Loader/FileSystemLoaderTest.php
+++ b/tests/Binary/Loader/FileSystemLoaderTest.php
@@ -178,7 +178,7 @@ private function getDefaultDataRoots(): array
         return [__DIR__];
     }
 
-    private function getFileSystemLoader(array $roots = [], LocatorInterface $locator = null): FileSystemLoader
+    private function getFileSystemLoader(array $roots = [], ?LocatorInterface $locator = null): FileSystemLoader
     {
         $mimeTypes = MimeTypes::getDefault();
 
diff --git a/tests/Component/Console/Style/ImagineStyleTest.php b/tests/Component/Console/Style/ImagineStyleTest.php
index f9e2dbd8e..651dc0eb0 100644
--- a/tests/Component/Console/Style/ImagineStyleTest.php
+++ b/tests/Component/Console/Style/ImagineStyleTest.php
@@ -97,7 +97,7 @@ public static function provideNewlineData(): \Generator
     /**
      * @dataProvider provideTitleData
      */
-    public function testTitle(string $title, string $type = null, bool $decoration): void
+    public function testTitle(string $title, ?string $type, bool $decoration): void
     {
         $style = $this->createImagineStyle($output = $this->createBufferedOutput(), $decoration);
         $style->title($title, $type);
@@ -174,7 +174,7 @@ public static function provideBlockTypesData(): \Generator
     /**
      * @dataProvider provideStatusData
      */
-    public function testStatus(string $status, string $fg = null, string $bg = null): void
+    public function testStatus(string $status, ?string $fg = null, ?string $bg = null): void
     {
         $style = $this->createImagineStyle($output = $this->createBufferedOutput());
         $style->status($status, $fg);
@@ -198,7 +198,7 @@ public static function provideStatusData(): \Generator
     /**
      * @dataProvider provideGroupData
      */
-    public function testGroup(string $item, string $group, string $fg = null, string $bg = null): void
+    public function testGroup(string $item, string $group, ?string $fg = null, ?string $bg = null): void
     {
         $style = $this->createImagineStyle($output = $this->createBufferedOutput());
         $style->group($item, $group, $fg, $bg);
diff --git a/tests/DependencyInjection/Factory/Resolver/AwsS3ResolverFactoryTest.php b/tests/DependencyInjection/Factory/Resolver/AwsS3ResolverFactoryTest.php
index 28110f489..c988a6d07 100644
--- a/tests/DependencyInjection/Factory/Resolver/AwsS3ResolverFactoryTest.php
+++ b/tests/DependencyInjection/Factory/Resolver/AwsS3ResolverFactoryTest.php
@@ -379,7 +379,7 @@ public function testAddDefaultOptionsIfNotSetOnAddConfiguration(): void
         $this->assertSame([], $config['get_options']);
 
         $this->assertArrayHasKey('cache_prefix', $config);
-        $this->assertNull($config['cache_prefix']);
+        $this->assertSame('', $config['cache_prefix']);
     }
 
     public function testSupportAwsV3ClientConfig(): void
diff --git a/tests/Functional/Command/RemoveCacheCommandTest.php b/tests/Functional/Command/RemoveCacheCommandTest.php
index 8db83d7c4..5aec1d601 100644
--- a/tests/Functional/Command/RemoveCacheCommandTest.php
+++ b/tests/Functional/Command/RemoveCacheCommandTest.php
@@ -216,7 +216,7 @@ protected function assertOutputNotContainsSummary(string $output, array $images,
      * @param string[] $filters
      * @param string[] $additionalOptions
      */
-    private function executeRemoveCacheCommand(array $paths, array $filters = [], array $additionalOptions = [], int &$return = null): string
+    private function executeRemoveCacheCommand(array $paths, array $filters = [], array $additionalOptions = [], ?int &$return = null): string
     {
         $options = array_merge(['paths' => $paths], $additionalOptions);
 
diff --git a/tests/Functional/Command/ResolveCacheCommandTest.php b/tests/Functional/Command/ResolveCacheCommandTest.php
index 364100d53..07194b7f9 100644
--- a/tests/Functional/Command/ResolveCacheCommandTest.php
+++ b/tests/Functional/Command/ResolveCacheCommandTest.php
@@ -219,7 +219,7 @@ protected function assertOutputNotContainsSummary(string $output, array $images,
      * @param string[] $filters
      * @param string[] $additionalOptions
      */
-    private function executeResolveCacheCommand(array $paths, array $filters = [], array $additionalOptions = [], int &$return = null): string
+    private function executeResolveCacheCommand(array $paths, array $filters = [], array $additionalOptions = [], ?int &$return = null): string
     {
         $options = array_merge(['paths' => $paths], $additionalOptions);
 
diff --git a/tests/Imagine/Filter/Loader/ResampleFilterLoaderTest.php b/tests/Imagine/Filter/Loader/ResampleFilterLoaderTest.php
index 7dfffe1b0..42dae672d 100644
--- a/tests/Imagine/Filter/Loader/ResampleFilterLoaderTest.php
+++ b/tests/Imagine/Filter/Loader/ResampleFilterLoaderTest.php
@@ -175,7 +175,7 @@ public function testThrowsOnSaveOrOpenError(): void
         $this->createResampleFilterLoaderInstance()->load($image, ['x' => 120, 'y' => 120, 'unit' => 'ppi']);
     }
 
-    private function createResampleFilterLoaderInstance(ImagineInterface $imagine = null): ResampleFilterLoader
+    private function createResampleFilterLoaderInstance(?ImagineInterface $imagine = null): ResampleFilterLoader
     {
         return new ResampleFilterLoader($imagine ?: $this->createMock(ImagineInterface::class));
     }