diff --git a/fastapi/openapi/utils.py b/fastapi/openapi/utils.py
index 271acd931..dc35124ee 100644
--- a/fastapi/openapi/utils.py
+++ b/fastapi/openapi/utils.py
@@ -347,7 +347,9 @@ def get_openapi_path(
                         response_schema = {}
 
                 route_responses = {str(k): v for k, v in route.responses.items()}
-                if status_code not in route_responses or not route_responses.get(status_code, {}).get('superimpose'):
+                if status_code not in route_responses or not route_responses.get(
+                    status_code, {}
+                ).get("superimpose"):
                     operation.setdefault("responses", {}).setdefault(
                         status_code, {}
                     ).setdefault("content", {}).setdefault(