diff --git a/.github/workflows/phpunit.yml b/.github/workflows/phpunit.yml
index ba2b657..f7d766c 100644
--- a/.github/workflows/phpunit.yml
+++ b/.github/workflows/phpunit.yml
@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2"
+        uses: "actions/checkout@v4"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"
@@ -34,7 +34,7 @@ jobs:
           tools: composer:v2, cs2pr
 
       - name: "Cache dependencies"
-        uses: "actions/cache@v2"
+        uses: "actions/cache@v4"
         with:
           path: |
             ~/.composer/cache
diff --git a/src/Locator/ComposerLocator.php b/src/Locator/ComposerLocator.php
index 31a7da0..7fe0634 100644
--- a/src/Locator/ComposerLocator.php
+++ b/src/Locator/ComposerLocator.php
@@ -28,7 +28,7 @@ class ComposerLocator implements LocatorInterface
      */
     private $loader;
 
-    public function __construct(ClassLoader $composerLoader = null)
+    public function __construct(?ClassLoader $composerLoader = null)
     {
         if ($composerLoader === null) {
             $loaders = spl_autoload_functions();
diff --git a/src/ReflectionProperty.php b/src/ReflectionProperty.php
index 9f40490..7d7ec1c 100644
--- a/src/ReflectionProperty.php
+++ b/src/ReflectionProperty.php
@@ -68,8 +68,8 @@ class ReflectionProperty extends BaseReflectionProperty
     public function __construct(
         string             $className,
         string             $propertyName,
-        Property|Param     $propertyOrPromotedParam = null,
-        PropertyItem|Param $propertyItemOrPromotedParam = null
+        Property|Param|null     $propertyOrPromotedParam = null,
+        PropertyItem|Param|null $propertyItemOrPromotedParam = null
     ) {
         $this->className = ltrim($className, '\\');
         if (!$propertyOrPromotedParam || !$propertyItemOrPromotedParam) {