diff --git a/composer.json b/composer.json
index 82281999..14a561c0 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
     "phpstan/phpstan": "1.10.25",
     "phpunit/phpunit": "^8.0|^9.0",
     "rregeer/phpunit-coverage-check": "^0.3.1",
-    "slevomat/coding-standard": "^6.4",
+    "slevomat/coding-standard": "^8.15",
     "squizlabs/php_codesniffer": "^3.5",
     "supportpal/coding-standard": "^0.4"
   },
diff --git a/composer.lock b/composer.lock
index 77e7e49e..a4a0da9e 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "5db9e6811186aa814fa8e66a922cbc7f",
+    "content-hash": "d320eb12aa8d323040e0aecb065e8925",
     "packages": [
         {
             "name": "doctrine/annotations",
@@ -771,28 +771,35 @@
         },
         {
             "name": "phpdocumentor/reflection-docblock",
-            "version": "5.3.0",
+            "version": "5.4.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/ReflectionDocBlock.git",
-                "reference": "622548b623e81ca6d78b721c5e029f4ce664f170"
+                "reference": "298d2febfe79d03fe714eb871d5538da55205b1a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/622548b623e81ca6d78b721c5e029f4ce664f170",
-                "reference": "622548b623e81ca6d78b721c5e029f4ce664f170",
+                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/298d2febfe79d03fe714eb871d5538da55205b1a",
+                "reference": "298d2febfe79d03fe714eb871d5538da55205b1a",
                 "shasum": ""
             },
             "require": {
+                "doctrine/deprecations": "^1.1",
                 "ext-filter": "*",
-                "php": "^7.2 || ^8.0",
+                "php": "^7.4 || ^8.0",
                 "phpdocumentor/reflection-common": "^2.2",
-                "phpdocumentor/type-resolver": "^1.3",
+                "phpdocumentor/type-resolver": "^1.7",
+                "phpstan/phpdoc-parser": "^1.7",
                 "webmozart/assert": "^1.9.1"
             },
             "require-dev": {
-                "mockery/mockery": "~1.3.2",
-                "psalm/phar": "^4.8"
+                "mockery/mockery": "~1.3.5",
+                "phpstan/extension-installer": "^1.1",
+                "phpstan/phpstan": "^1.8",
+                "phpstan/phpstan-mockery": "^1.1",
+                "phpstan/phpstan-webmozart-assert": "^1.2",
+                "phpunit/phpunit": "^9.5",
+                "vimeo/psalm": "^5.13"
             },
             "type": "library",
             "extra": {
@@ -816,36 +823,39 @@
                 },
                 {
                     "name": "Jaap van Otterdijk",
-                    "email": "account@ijaap.nl"
+                    "email": "opensource@ijaap.nl"
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
             "support": {
                 "issues": "https://github.com/phpDocumentor/ReflectionDocBlock/issues",
-                "source": "https://github.com/phpDocumentor/ReflectionDocBlock/tree/5.3.0"
+                "source": "https://github.com/phpDocumentor/ReflectionDocBlock/tree/5.4.0"
             },
-            "time": "2021-10-19T17:43:47+00:00"
+            "time": "2024-04-09T21:13:58+00:00"
         },
         {
             "name": "phpdocumentor/type-resolver",
-            "version": "1.6.2",
+            "version": "1.8.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/TypeResolver.git",
-                "reference": "48f445a408c131e38cab1c235aa6d2bb7a0bb20d"
+                "reference": "153ae662783729388a584b4361f2545e4d841e3c"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/TypeResolver/zipball/48f445a408c131e38cab1c235aa6d2bb7a0bb20d",
-                "reference": "48f445a408c131e38cab1c235aa6d2bb7a0bb20d",
+                "url": "https://api.github.com/repos/phpDocumentor/TypeResolver/zipball/153ae662783729388a584b4361f2545e4d841e3c",
+                "reference": "153ae662783729388a584b4361f2545e4d841e3c",
                 "shasum": ""
             },
             "require": {
-                "php": "^7.4 || ^8.0",
-                "phpdocumentor/reflection-common": "^2.0"
+                "doctrine/deprecations": "^1.0",
+                "php": "^7.3 || ^8.0",
+                "phpdocumentor/reflection-common": "^2.0",
+                "phpstan/phpdoc-parser": "^1.13"
             },
             "require-dev": {
                 "ext-tokenizer": "*",
+                "phpbench/phpbench": "^1.2",
                 "phpstan/extension-installer": "^1.1",
                 "phpstan/phpstan": "^1.8",
                 "phpstan/phpstan-phpunit": "^1.1",
@@ -877,9 +887,56 @@
             "description": "A PSR-5 based resolver of Class names, Types and Structural Element Names",
             "support": {
                 "issues": "https://github.com/phpDocumentor/TypeResolver/issues",
-                "source": "https://github.com/phpDocumentor/TypeResolver/tree/1.6.2"
+                "source": "https://github.com/phpDocumentor/TypeResolver/tree/1.8.2"
+            },
+            "time": "2024-02-23T11:10:43+00:00"
+        },
+        {
+            "name": "phpstan/phpdoc-parser",
+            "version": "1.29.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpstan/phpdoc-parser.git",
+                "reference": "536889f2b340489d328f5ffb7b02bb6b183ddedc"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpdoc-parser/zipball/536889f2b340489d328f5ffb7b02bb6b183ddedc",
+                "reference": "536889f2b340489d328f5ffb7b02bb6b183ddedc",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.2 || ^8.0"
+            },
+            "require-dev": {
+                "doctrine/annotations": "^2.0",
+                "nikic/php-parser": "^4.15",
+                "php-parallel-lint/php-parallel-lint": "^1.2",
+                "phpstan/extension-installer": "^1.0",
+                "phpstan/phpstan": "^1.5",
+                "phpstan/phpstan-phpunit": "^1.1",
+                "phpstan/phpstan-strict-rules": "^1.0",
+                "phpunit/phpunit": "^9.5",
+                "symfony/process": "^5.2"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "PHPStan\\PhpDocParser\\": [
+                        "src/"
+                    ]
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "PHPDoc parser with support for nullable, intersection and generic types",
+            "support": {
+                "issues": "https://github.com/phpstan/phpdoc-parser/issues",
+                "source": "https://github.com/phpstan/phpdoc-parser/tree/1.29.0"
             },
-            "time": "2022-10-14T12:47:21+00:00"
+            "time": "2024-05-06T12:04:23+00:00"
         },
         {
             "name": "psr/cache",
@@ -2719,35 +2776,38 @@
         },
         {
             "name": "dealerdirect/phpcodesniffer-composer-installer",
-            "version": "v0.7.2",
+            "version": "v1.0.0",
             "source": {
                 "type": "git",
-                "url": "https://github.com/Dealerdirect/phpcodesniffer-composer-installer.git",
-                "reference": "1c968e542d8843d7cd71de3c5c9c3ff3ad71a1db"
+                "url": "https://github.com/PHPCSStandards/composer-installer.git",
+                "reference": "4be43904336affa5c2f70744a348312336afd0da"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/Dealerdirect/phpcodesniffer-composer-installer/zipball/1c968e542d8843d7cd71de3c5c9c3ff3ad71a1db",
-                "reference": "1c968e542d8843d7cd71de3c5c9c3ff3ad71a1db",
+                "url": "https://api.github.com/repos/PHPCSStandards/composer-installer/zipball/4be43904336affa5c2f70744a348312336afd0da",
+                "reference": "4be43904336affa5c2f70744a348312336afd0da",
                 "shasum": ""
             },
             "require": {
                 "composer-plugin-api": "^1.0 || ^2.0",
-                "php": ">=5.3",
+                "php": ">=5.4",
                 "squizlabs/php_codesniffer": "^2.0 || ^3.1.0 || ^4.0"
             },
             "require-dev": {
                 "composer/composer": "*",
+                "ext-json": "*",
+                "ext-zip": "*",
                 "php-parallel-lint/php-parallel-lint": "^1.3.1",
-                "phpcompatibility/php-compatibility": "^9.0"
+                "phpcompatibility/php-compatibility": "^9.0",
+                "yoast/phpunit-polyfills": "^1.0"
             },
             "type": "composer-plugin",
             "extra": {
-                "class": "Dealerdirect\\Composer\\Plugin\\Installers\\PHPCodeSniffer\\Plugin"
+                "class": "PHPCSStandards\\Composer\\Plugin\\Installers\\PHPCodeSniffer\\Plugin"
             },
             "autoload": {
                 "psr-4": {
-                    "Dealerdirect\\Composer\\Plugin\\Installers\\PHPCodeSniffer\\": "src/"
+                    "PHPCSStandards\\Composer\\Plugin\\Installers\\PHPCodeSniffer\\": "src/"
                 }
             },
             "notification-url": "https://packagist.org/downloads/",
@@ -2763,7 +2823,7 @@
                 },
                 {
                     "name": "Contributors",
-                    "homepage": "https://github.com/Dealerdirect/phpcodesniffer-composer-installer/graphs/contributors"
+                    "homepage": "https://github.com/PHPCSStandards/composer-installer/graphs/contributors"
                 }
             ],
             "description": "PHP_CodeSniffer Standards Composer Installer Plugin",
@@ -2787,10 +2847,10 @@
                 "tests"
             ],
             "support": {
-                "issues": "https://github.com/dealerdirect/phpcodesniffer-composer-installer/issues",
-                "source": "https://github.com/dealerdirect/phpcodesniffer-composer-installer"
+                "issues": "https://github.com/PHPCSStandards/composer-installer/issues",
+                "source": "https://github.com/PHPCSStandards/composer-installer"
             },
-            "time": "2022-02-04T12:51:07+00:00"
+            "time": "2023-01-05T11:28:13+00:00"
         },
         {
             "name": "doctrine/instantiator",
@@ -3583,59 +3643,6 @@
             },
             "time": "2024-03-01T08:33:58+00:00"
         },
-        {
-            "name": "phpstan/phpdoc-parser",
-            "version": "0.4.9",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/phpstan/phpdoc-parser.git",
-                "reference": "98a088b17966bdf6ee25c8a4b634df313d8aa531"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpdoc-parser/zipball/98a088b17966bdf6ee25c8a4b634df313d8aa531",
-                "reference": "98a088b17966bdf6ee25c8a4b634df313d8aa531",
-                "shasum": ""
-            },
-            "require": {
-                "php": "^7.1 || ^8.0"
-            },
-            "require-dev": {
-                "consistence/coding-standard": "^3.5",
-                "ergebnis/composer-normalize": "^2.0.2",
-                "jakub-onderka/php-parallel-lint": "^0.9.2",
-                "phing/phing": "^2.16.0",
-                "phpstan/extension-installer": "^1.0",
-                "phpstan/phpstan": "^0.12.26",
-                "phpstan/phpstan-strict-rules": "^0.12",
-                "phpunit/phpunit": "^6.3",
-                "slevomat/coding-standard": "^4.7.2",
-                "symfony/process": "^4.0"
-            },
-            "type": "library",
-            "extra": {
-                "branch-alias": {
-                    "dev-master": "0.4-dev"
-                }
-            },
-            "autoload": {
-                "psr-4": {
-                    "PHPStan\\PhpDocParser\\": [
-                        "src/"
-                    ]
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "description": "PHPDoc parser with support for nullable, intersection and generic types",
-            "support": {
-                "issues": "https://github.com/phpstan/phpdoc-parser/issues",
-                "source": "https://github.com/phpstan/phpdoc-parser/tree/master"
-            },
-            "time": "2020-08-03T20:32:43+00:00"
-        },
         {
             "name": "phpstan/phpstan",
             "version": "1.10.25",
@@ -5181,42 +5188,42 @@
         },
         {
             "name": "slevomat/coding-standard",
-            "version": "6.4.1",
+            "version": "8.15.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/slevomat/coding-standard.git",
-                "reference": "696dcca217d0c9da2c40d02731526c1e25b65346"
+                "reference": "7d1d957421618a3803b593ec31ace470177d7817"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/slevomat/coding-standard/zipball/696dcca217d0c9da2c40d02731526c1e25b65346",
-                "reference": "696dcca217d0c9da2c40d02731526c1e25b65346",
+                "url": "https://api.github.com/repos/slevomat/coding-standard/zipball/7d1d957421618a3803b593ec31ace470177d7817",
+                "reference": "7d1d957421618a3803b593ec31ace470177d7817",
                 "shasum": ""
             },
             "require": {
-                "dealerdirect/phpcodesniffer-composer-installer": "^0.6.2 || ^0.7",
-                "php": "^7.1 || ^8.0",
-                "phpstan/phpdoc-parser": "0.4.5 - 0.4.9",
-                "squizlabs/php_codesniffer": "^3.5.6"
+                "dealerdirect/phpcodesniffer-composer-installer": "^0.6.2 || ^0.7 || ^1.0",
+                "php": "^7.2 || ^8.0",
+                "phpstan/phpdoc-parser": "^1.23.1",
+                "squizlabs/php_codesniffer": "^3.9.0"
             },
             "require-dev": {
-                "phing/phing": "2.16.3",
-                "php-parallel-lint/php-parallel-lint": "1.2.0",
-                "phpstan/phpstan": "0.12.48",
-                "phpstan/phpstan-deprecation-rules": "0.12.5",
-                "phpstan/phpstan-phpunit": "0.12.16",
-                "phpstan/phpstan-strict-rules": "0.12.5",
-                "phpunit/phpunit": "7.5.20|8.5.5|9.4.0"
+                "phing/phing": "2.17.4",
+                "php-parallel-lint/php-parallel-lint": "1.3.2",
+                "phpstan/phpstan": "1.10.60",
+                "phpstan/phpstan-deprecation-rules": "1.1.4",
+                "phpstan/phpstan-phpunit": "1.3.16",
+                "phpstan/phpstan-strict-rules": "1.5.2",
+                "phpunit/phpunit": "8.5.21|9.6.8|10.5.11"
             },
             "type": "phpcodesniffer-standard",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "6.x-dev"
+                    "dev-master": "8.x-dev"
                 }
             },
             "autoload": {
                 "psr-4": {
-                    "SlevomatCodingStandard\\": "SlevomatCodingStandard"
+                    "SlevomatCodingStandard\\": "SlevomatCodingStandard/"
                 }
             },
             "notification-url": "https://packagist.org/downloads/",
@@ -5224,9 +5231,13 @@
                 "MIT"
             ],
             "description": "Slevomat Coding Standard for PHP_CodeSniffer complements Consistence Coding Standard by providing sniffs with additional checks.",
+            "keywords": [
+                "dev",
+                "phpcs"
+            ],
             "support": {
                 "issues": "https://github.com/slevomat/coding-standard/issues",
-                "source": "https://github.com/slevomat/coding-standard/tree/6.4.1"
+                "source": "https://github.com/slevomat/coding-standard/tree/8.15.0"
             },
             "funding": [
                 {
@@ -5238,7 +5249,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2020-10-05T12:39:37+00:00"
+            "time": "2024-03-09T15:20:58+00:00"
         },
         {
             "name": "squizlabs/php_codesniffer",
@@ -5322,20 +5333,20 @@
         },
         {
             "name": "supportpal/coding-standard",
-            "version": "v0.4.1",
+            "version": "v0.4.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/supportpal/coding-standard.git",
-                "reference": "b40eac00a23eaa5f54183d88814e2ec80b72c6f2"
+                "reference": "5556ca6461a866ddbf1cf8ff41544543c55a3719"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/supportpal/coding-standard/zipball/b40eac00a23eaa5f54183d88814e2ec80b72c6f2",
-                "reference": "b40eac00a23eaa5f54183d88814e2ec80b72c6f2",
+                "url": "https://api.github.com/repos/supportpal/coding-standard/zipball/5556ca6461a866ddbf1cf8ff41544543c55a3719",
+                "reference": "5556ca6461a866ddbf1cf8ff41544543c55a3719",
                 "shasum": ""
             },
             "require": {
-                "slevomat/coding-standard": "^6.3|^7.0|^8.0"
+                "slevomat/coding-standard": "^8.0"
             },
             "type": "library",
             "notification-url": "https://packagist.org/downloads/",
@@ -5351,9 +5362,9 @@
             "description": "SupportPal PHP coding standard.",
             "support": {
                 "issues": "https://github.com/supportpal/coding-standard/issues",
-                "source": "https://github.com/supportpal/coding-standard/tree/v0.4.1"
+                "source": "https://github.com/supportpal/coding-standard/tree/v0.4.4"
             },
-            "time": "2023-03-09T11:15:16+00:00"
+            "time": "2023-03-09T12:36:40+00:00"
         },
         {
             "name": "symfony/console",
diff --git a/src/Config/RequestDefaults.php b/src/Config/RequestDefaults.php
index 8a7e207c..cc9df26a 100644
--- a/src/Config/RequestDefaults.php
+++ b/src/Config/RequestDefaults.php
@@ -103,7 +103,7 @@ public function setDefaultRequestOptions(array $defaultRequestOptions): self
      * @param mixed $value
      * @return $this
      */
-    public function addRequestOption(string $key, $value): self
+    public function addRequestOption(string $key, mixed $value): self
     {
         $this->defaultRequestOptions[$key] = $value;
 
diff --git a/src/Model/BaseModel.php b/src/Model/BaseModel.php
index b1724f0e..5cf30402 100644
--- a/src/Model/BaseModel.php
+++ b/src/Model/BaseModel.php
@@ -123,7 +123,7 @@ public function setPivot(?array $pivot): self
      * @param mixed $value
      * @return mixed
      */
-    private function applyAttributeAwareTransformers(array $attributeAwareTransformers, string $key, $value)
+    private function applyAttributeAwareTransformers(array $attributeAwareTransformers, string $key, mixed $value)
     {
         foreach ($attributeAwareTransformers as $transformer) {
             if (! $transformer->canTransform($this->snakeCaseToCamelCase($key), get_class($this), $value)) {
@@ -141,7 +141,7 @@ private function applyAttributeAwareTransformers(array $attributeAwareTransforme
      * @param mixed $value
      * @throws InvalidArgumentException
      */
-    private function setAttributeValue(string $attributeSetter, $value): void
+    private function setAttributeValue(string $attributeSetter, mixed $value): void
     {
         try {
             $this->{$attributeSetter}($value);
@@ -159,7 +159,7 @@ private function setAttributeValue(string $attributeSetter, $value): void
      * @param mixed $value
      * @return mixed
      */
-    private function applyValueTransformers(array $transformers, $value)
+    private function applyValueTransformers(array $transformers, mixed $value)
     {
         foreach ($transformers as $transformer) {
             if (! $transformer->canTransform($value)) {
diff --git a/src/Model/Department/Email.php b/src/Model/Department/Email.php
index fbd4ed2e..c289a860 100644
--- a/src/Model/Department/Email.php
+++ b/src/Model/Department/Email.php
@@ -165,7 +165,7 @@ public function getDepartmentId(): int
      * @param string|int $departmentId
      * @return self
      */
-    public function setDepartmentId($departmentId): self
+    public function setDepartmentId(string|int $departmentId): self
     {
         $departmentId = filter_var($departmentId, FILTER_VALIDATE_INT);
 
diff --git a/src/Model/SettingsModel.php b/src/Model/SettingsModel.php
index ea6dc448..91a3abd8 100644
--- a/src/Model/SettingsModel.php
+++ b/src/Model/SettingsModel.php
@@ -9,7 +9,7 @@ interface SettingsModel extends Model
      * @param mixed $value
      * @return void
      */
-    public function __set($property, $value);
+    public function __set(mixed $property, mixed $value);
 
     /**
      * @return string[]
@@ -21,5 +21,5 @@ public function all(): array;
      * @param mixed|null $default
      * @return string|null
      */
-    public function get(string $name, $default = null): ?string;
+    public function get(string $name, mixed $default = null): ?string;
 }
diff --git a/src/Transformer/AttributeAwareTransformer.php b/src/Transformer/AttributeAwareTransformer.php
index 6b13bf6b..20cd9f6f 100644
--- a/src/Transformer/AttributeAwareTransformer.php
+++ b/src/Transformer/AttributeAwareTransformer.php
@@ -10,11 +10,11 @@ interface AttributeAwareTransformer
      * @param mixed $value
      * @return bool
      */
-    public function canTransform(string $attribute, string $type, $value): bool;
+    public function canTransform(string $attribute, string $type, mixed $value): bool;
 
     /**
      * @param mixed $value
      * @return mixed
      */
-    public function transform($value);
+    public function transform(mixed $value);
 }
diff --git a/src/Transformer/Transformer.php b/src/Transformer/Transformer.php
index 91219947..22473cfb 100644
--- a/src/Transformer/Transformer.php
+++ b/src/Transformer/Transformer.php
@@ -8,11 +8,11 @@ interface Transformer
      * @param mixed $value
      * @return bool
      */
-    public function canTransform($value): bool;
+    public function canTransform(mixed $value): bool;
 
     /**
      * @param mixed $value
      * @return mixed
      */
-    public function transform($value);
+    public function transform(mixed $value);
 }
diff --git a/test/TestCase.php b/test/TestCase.php
index bbc3c12f..b86e7483 100644
--- a/test/TestCase.php
+++ b/test/TestCase.php
@@ -86,7 +86,7 @@ protected function assertArrayEqualsObjectFields(object $obj, array $array): voi
      * @param Collection|Model $models
      * @param array<mixed> $data
      */
-    protected function assertApiDataMatchesModels($models, array $data): void
+    protected function assertApiDataMatchesModels(Model|Collection $models, array $data): void
     {
         if ($models instanceof Collection) {
             self::assertSame($data['count'], $models->getCount());
@@ -114,7 +114,7 @@ protected function assertApiDataMatchesModels($models, array $data): void
      * @param array<mixed> $attributeValue
      * @param mixed $value
      */
-    protected function handleNestedArrays(array $attributeValue, $value): void
+    protected function handleNestedArrays(array $attributeValue, mixed $value): void
     {
         for ($i = 0; $i < count($attributeValue); ++$i) {
             if (! is_object($value[$i])) {
@@ -131,7 +131,7 @@ protected function handleNestedArrays(array $attributeValue, $value): void
      * @param mixed $attributeValue
      * @param mixed $value
      */
-    protected function handleAtomicValues($attributeValue, $value): void
+    protected function handleAtomicValues(mixed $attributeValue, mixed $value): void
     {
         if (is_bool($attributeValue) || is_bool($value)) {
             /**
diff --git a/test/Unit/ModelNormalizer/ModelNormalizerTest.php b/test/Unit/ModelNormalizer/ModelNormalizerTest.php
index 843d0da4..b30d4c81 100644
--- a/test/Unit/ModelNormalizer/ModelNormalizerTest.php
+++ b/test/Unit/ModelNormalizer/ModelNormalizerTest.php
@@ -99,7 +99,7 @@ public function testNormalizeTransformAll(): void
      * @param bool $objectNormalizerSupports
      * @param bool $expectation
      */
-    public function testSupportsNormalization($data, bool $objectNormalizerSupports, bool $expectation): void
+    public function testSupportsNormalization(mixed $data, bool $objectNormalizerSupports, bool $expectation): void
     {
         $objectNormalizerExpectation = $this->objectNormalizer
             ->supportsNormalization($data, $this->format)
@@ -152,7 +152,7 @@ public function testNormalizeTransformNone(): void
      * @param bool $objectNormalizerSupports
      * @dataProvider provideSupportNormalizationCases
      */
-    public function testSupportsDenormalization($data, bool $objectNormalizerSupports): void
+    public function testSupportsDenormalization(mixed $data, bool $objectNormalizerSupports): void
     {
         $this->objectNormalizer
             ->supportsDenormalization($data, Model::class, $this->format)
diff --git a/test/Unit/Transformer/BooleanToIntTransformerTest.php b/test/Unit/Transformer/BooleanToIntTransformerTest.php
index 395c588c..c004778b 100644
--- a/test/Unit/Transformer/BooleanToIntTransformerTest.php
+++ b/test/Unit/Transformer/BooleanToIntTransformerTest.php
@@ -31,7 +31,7 @@ public function testCanTransform(bool $data): void
      * @param mixed $data
      * @dataProvider provideCannotTransformCases
      */
-    public function testCannotTransform($data): void
+    public function testCannotTransform(mixed $data): void
     {
         self::assertFalse($this->booleanToIntTransformer->canTransform($data));
     }
diff --git a/test/Unit/Transformer/EmptyModelToNullTransformerTest.php b/test/Unit/Transformer/EmptyModelToNullTransformerTest.php
index 88dae081..1d46cd13 100644
--- a/test/Unit/Transformer/EmptyModelToNullTransformerTest.php
+++ b/test/Unit/Transformer/EmptyModelToNullTransformerTest.php
@@ -66,7 +66,7 @@ public function testCanTransform(Model $model): void
      * @param mixed $data
      * @dataProvider provideCannotTransformCases
      */
-    public function testCannotTransform($data): void
+    public function testCannotTransform(mixed $data): void
     {
         self::assertFalse($this->transformer->canTransform($data));
     }
diff --git a/test/Unit/Transformer/IntToBooleanTransformerTest.php b/test/Unit/Transformer/IntToBooleanTransformerTest.php
index 433df6c4..8ad8e177 100644
--- a/test/Unit/Transformer/IntToBooleanTransformerTest.php
+++ b/test/Unit/Transformer/IntToBooleanTransformerTest.php
@@ -41,7 +41,7 @@ protected function setUp(): void
      * @param mixed $value
      * @dataProvider provideCannotTransformNonIntValueCases
      */
-    public function testCannotTransformNonIntValue($value): void
+    public function testCannotTransformNonIntValue(mixed $value): void
     {
         $this->propertyTypeExtractor->getTypes(Model::class, $this->attribute)->shouldNotBeCalled();
         self::assertFalse($this->intToBooleanTransformer->canTransform($this->attribute, Model::class, $value));
diff --git a/test/Unit/Transformer/StringTrimTransformerTest.php b/test/Unit/Transformer/StringTrimTransformerTest.php
index 56ecc802..1a73cf18 100644
--- a/test/Unit/Transformer/StringTrimTransformerTest.php
+++ b/test/Unit/Transformer/StringTrimTransformerTest.php
@@ -33,7 +33,7 @@ public function testCanTransform(): void
      * @param mixed $data
      * @dataProvider provideCannotTransformCases
      */
-    public function testCannotTransform($data): void
+    public function testCannotTransform(mixed $data): void
     {
         self::assertFalse($this->transformer->canTransform($data));
     }