diff --git a/src/Resources/Concerns/ToResponse.php b/src/Resources/Concerns/ToResponse.php
index 6555bf2..185b348 100644
--- a/src/Resources/Concerns/ToResponse.php
+++ b/src/Resources/Concerns/ToResponse.php
@@ -14,6 +14,6 @@ public function toResponse($request): JsonResponse
     {
         return parent
             ::toResponse($request)
-            ->header('Content-type', 'application/vnd.api+json');
+            ->header('Content-Type', 'application/vnd.api+json');
     }
 }