diff --git a/tests/Generator/Request/ParametersDocumentationTest.php b/tests/Generator/Request/ParametersDocumentationTest.php
index d429043a..6c54a16a 100644
--- a/tests/Generator/Request/ParametersDocumentationTest.php
+++ b/tests/Generator/Request/ParametersDocumentationTest.php
@@ -81,6 +81,7 @@ public function __invoke(Request $request)
                 'type' => ['string', 'null'],
                 'default' => 'paypal',
             ],
+            'x-optional' => true,
         ]);
 });