diff --git a/fastapi/routing.py b/fastapi/routing.py
index 5f9eda87c6..c0cc36296d 100644
--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -1412,12 +1412,8 @@ class APIRouter(routing.Router):
             "openapi_extra": openapi_extra,
             "generate_unique_id_function": current_generate_unique_id,
         }
-        if (
-            "strict_content_type" in route_init_params
-            or any(
-                p.kind == inspect.Parameter.VAR_KEYWORD
-                for p in route_init_params.values()
-            )
+        if "strict_content_type" in route_init_params or any(
+            p.kind == inspect.Parameter.VAR_KEYWORD for p in route_init_params.values()
         ):
             route_kwargs["strict_content_type"] = get_value_or_default(
                 strict_content_type, self.strict_content_type
diff --git a/tests/test_custom_route_class.py b/tests/test_custom_route_class.py
index 49ce7768a4..214aaae89d 100644
--- a/tests/test_custom_route_class.py
+++ b/tests/test_custom_route_class.py
@@ -1,6 +1,6 @@
-from collections.abc import Sequence
+from collections.abc import Callable, Sequence
 from enum import Enum
-from typing import Any, Callable
+from typing import Any
 
 import pytest
 from fastapi import APIRouter, FastAPI, params
@@ -128,6 +128,7 @@ def test_openapi_schema():
         }
     )
 
+
 def test_custom_api_route_without_strict_content_type():
     """
     Regression test for #15503:
@@ -212,6 +213,7 @@ def test_custom_api_route_without_strict_content_type():
     assert response.status_code == 200
     assert response.json() == {"ok": True}
 
+
 def test_custom_api_route_with_kwargs():
     """
     Custom APIRoute classes using **kwargs should still receive
@@ -219,7 +221,9 @@ def test_custom_api_route_with_kwargs():
     """
 
     class KwargsRoute(APIRoute):
-        def __init__(self, path: str, endpoint: Callable[..., Any], **kwargs: Any) -> None:
+        def __init__(
+            self, path: str, endpoint: Callable[..., Any], **kwargs: Any
+        ) -> None:
             super().__init__(path, endpoint, **kwargs)
 
     app_kwargs = FastAPI()