diff --git a/.github/workflows/php-tests.yml b/.github/workflows/php-tests.yml
index a102434c..9447d363 100644
--- a/.github/workflows/php-tests.yml
+++ b/.github/workflows/php-tests.yml
@@ -13,10 +13,14 @@ jobs:
     strategy:
       matrix:
         laravel: ['9', '10', '11']
-        php: ['8.1', '8.2', '8.3']
+        php: ['8.1', '8.2', '8.3', '8.4']
         exclude:
           - laravel: '11'
             php: '8.1'
+          - laravel: '9'
+            php: '8.4'
+          - laravel: '10'
+            php: '8.4'
 
     name: PHP ${{ matrix.php }} Laravel ${{ matrix.laravel }}
 
diff --git a/tests/JsValidationServiceProviderTest.php b/tests/JsValidationServiceProviderTest.php
index 0de17301..c9bb5307 100644
--- a/tests/JsValidationServiceProviderTest.php
+++ b/tests/JsValidationServiceProviderTest.php
@@ -111,7 +111,7 @@ public function testRegister()
         $mock->register();
     }
 
-    protected function assertConfigMerged(string $file, string $configKey = null): void
+    protected function assertConfigMerged(string $file, ?string $configKey = null): void
     {
         $configKey ??= Str::of($file)->beforeLast('.php')->afterLast('/')->afterLast('\\')->toString();