diff --git a/integration_tests/base_routes.py b/integration_tests/base_routes.py
index bcb1f4b9c..3cf5e0420 100644
--- a/integration_tests/base_routes.py
+++ b/integration_tests/base_routes.py
@@ -117,14 +117,14 @@ def global_before_request(request: Request):
 
 @app.after_request()
 def global_after_request(response: Response):
-    response.headers["global_after"] = [ "global_after_request" ]
+    response.headers["global_after"] = ["global_after_request"]
     return response
 
 
 @app.get("/sync/global/middlewares")
 def sync_global_middlewares(request: Request):
     assert "global_before" in request.headers
-    assert request.headers["global_before"] == [ "global_before_request" ]
+    assert request.headers["global_before"] == ["global_before_request"]
     return "sync global middlewares"
 
 
@@ -160,7 +160,7 @@ async def async_before_request(request: Request):
 
 @app.after_request("/async/middlewares")
 async def async_after_request(response: Response):
-    response.headers["after"] = [ "async_after_request" ]
+    response.headers["after"] = ["async_after_request"]
     response.description = response.description + " after"
     return response
 
@@ -271,7 +271,7 @@ def sync_response_get():
 
 @app.get("/async/response")
 async def async_response_get():
-    return Response(200, {"async": [ "response" ]}, "async response get")
+    return Response(200, {"async": ["response"]}, "async response get")
 
 
 @app.get("/sync/response/const", const=True)
@@ -477,7 +477,7 @@ async def redirect():
         "status_code": 307,
         "description": "",
         "type": "text",
-        "headers": {"Location": [ "redirect_route" ]},
+        "headers": {"Location": ["redirect_route"]},
     }
 
 
@@ -507,7 +507,7 @@ def sync_dict_post():
         "status_code": 200,
         "description": "sync dict post",
         "type": "text",
-        "headers": {"sync": [ "dict" ]},
+        "headers": {"sync": ["dict"]},
     }
 
 
@@ -517,7 +517,7 @@ async def async_dict_post():
         "status_code": 200,
         "description": "async dict post",
         "type": "text",
-        "headers": {"async": [ "dict" ]},
+        "headers": {"async": ["dict"]},
     }
 
 
@@ -564,7 +564,7 @@ def sync_dict_put():
         "status_code": 200,
         "description": "sync dict put",
         "type": "text",
-        "headers": {"sync": [ "dict" ]},
+        "headers": {"sync": ["dict"]},
     }
 
 
@@ -574,7 +574,7 @@ async def async_dict_put():
         "status_code": 200,
         "description": "async dict put",
         "type": "text",
-        "headers": {"async": [ "dict" ]},
+        "headers": {"async": ["dict"]},
     }
 
 
@@ -640,7 +640,7 @@ def sync_dict_patch():
         "status_code": 200,
         "description": "sync dict patch",
         "type": "text",
-        "headers": {"sync": [ "dict" ]},
+        "headers": {"sync": ["dict"]},
     }