diff --git a/.github/workflows/static.yml b/.github/workflows/static.yml
index 66fa7de..552cd99 100644
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@@ -57,7 +57,7 @@ jobs:
         with:
           php-version: 8.1
           coverage: none
-          tools: php-cs-fixer:3.21, cs2pr
+          tools: php-cs-fixer:3.92, cs2pr
 
       - name: Display PHP-CS-Fixer version
         run: php-cs-fixer --version
@@ -68,18 +68,18 @@ jobs:
 
   composer-normalize:
     name: Composer Normalize
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.2
+          php-version: 8.1
           coverage: none
           tools: composer-normalize
 
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Normalize
         run: composer-normalize --dry-run
diff --git a/src/ResponseFactory.php b/src/ResponseFactory.php
index 986ee16..cf17148 100644
--- a/src/ResponseFactory.php
+++ b/src/ResponseFactory.php
@@ -23,7 +23,7 @@ final class ResponseFactory
     private $cursor;
     private $contentType;
 
-    public function __construct(Manager $fractal, string $contentType = null)
+    public function __construct(Manager $fractal, ?string $contentType = null)
     {
         $this->fractal = $fractal;
         if (null === $contentType) {