diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 87668e5..ad0de0b 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -39,4 +39,4 @@ jobs:
           dependency-versions: ${{ matrix.dependency }}
 
       - name: Integration Tests
-        run: php ./vendor/bin/simple-phpunit
+        run: php ./vendor/bin/phpunit
diff --git a/composer.json b/composer.json
index e7b26ce..3268188 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
         "laravel/pint": "^1.24.0",
         "phpstan/phpstan": "^2.1.22",
         "rector/rector": "^2.1.5",
-        "symfony/phpunit-bridge": "^6.4.25|^7.3|^8.0",
+        "phpunit/phpunit": "^11|^12",
         "symfony/framework-bundle": "^6.4|^7.3|^8.0"
     },
     "autoload": {
diff --git a/src/OpenAIBundle.php b/src/OpenAIBundle.php
index 9d78a06..4974cee 100644
--- a/src/OpenAIBundle.php
+++ b/src/OpenAIBundle.php
@@ -28,8 +28,7 @@ public function configure(DefinitionConfigurator $definition): void
         $children
             ->scalarNode('api_key')
             ->defaultValue('%env(OPENAI_API_KEY)%')
-            ->info('OpenAI API Key used to authenticate with the OpenAI API')
-            ->isRequired();
+            ->info('OpenAI API Key used to authenticate with the OpenAI API');
         $children
             ->scalarNode('organization')
             ->info('OpenAI API Organization used to authenticate with the OpenAI API')
diff --git a/tests/OpenAIBundleTest.php b/tests/OpenAIBundleTest.php
index 960339f..2b7df64 100644
--- a/tests/OpenAIBundleTest.php
+++ b/tests/OpenAIBundleTest.php
@@ -7,10 +7,12 @@
 use OpenAI\Client;
 use OpenAI\Contracts\ClientContract;
 use OpenAI\Symfony\OpenAIBundle;
+use PHPUnit\Framework\Attributes\DoesNotPerformAssertions;
 use PHPUnit\Framework\TestCase;
 use Symfony\Bundle\FrameworkBundle\FrameworkBundle;
 use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+use Symfony\Component\ErrorHandler\ErrorHandler;
 use Symfony\Component\HttpClient\MockHttpClient;
 use Symfony\Component\HttpClient\Response\MockResponse;
 use Symfony\Component\HttpKernel\Kernel;
@@ -19,6 +21,38 @@
 
 final class OpenAIBundleTest extends TestCase
 {
+    public static function setUpBeforeClass(): void
+    {
+        ErrorHandler::register(null, false);
+    }
+
+    #[DoesNotPerformAssertions]
+    public function test_defaults(): void
+    {
+        $kernel = new class('test', true) extends Kernel
+        {
+            use MicroKernelTrait;
+
+            public function registerBundles(): iterable
+            {
+                yield new FrameworkBundle;
+                yield new OpenAIBundle;
+            }
+
+            protected function configureContainer(ContainerConfigurator $container): void
+            {
+                $container->extension('framework', [
+                    'secret' => 'S0ME_SECRET',
+                    'http_method_override' => false,
+                    'handle_all_throwables' => true,
+                    'php_errors' => ['log' => true],
+                ]);
+            }
+        };
+
+        $kernel->boot();
+    }
+
     public function test_service(): void
     {
         $kernel = new class('test', true) extends Kernel