diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 8cc5b7e..def3397 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: [8.1, 8.2, 8.3]
+        php: [8.1, 8.2, 8.3, 8.4]
         laravel: [9.*, 10.*, 11.*]
         exclude:
           - laravel: 11.*
diff --git a/src/Controllers/StoplightController.php b/src/Controllers/StoplightController.php
index c956f7c..6f58785 100644
--- a/src/Controllers/StoplightController.php
+++ b/src/Controllers/StoplightController.php
@@ -38,7 +38,7 @@ public function asset(string $asset, string $ext): Response
             ->setExpires(new DateTime('+1 year'));
     }
 
-    protected function distPath(string $asset = null): string
+    protected function distPath(?string $asset = null): string
     {
         $allowedFiles = [
             'web-components.min.js',