diff --git a/fastapi/routing.py b/fastapi/routing.py
index a13763535d..7fd1dd283c 100644
--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -73,9 +73,9 @@ from fastapi.utils import (
     is_body_allowed_for_status_code,
 )
 from starlette import routing
-from starlette.background import BackgroundTasks
 from starlette._exception_handler import wrap_app_handling_exceptions
 from starlette._utils import is_async_callable
+from starlette.background import BackgroundTasks
 from starlette.concurrency import iterate_in_threadpool, run_in_threadpool
 from starlette.datastructures import FormData
 from starlette.exceptions import HTTPException
@@ -684,9 +684,7 @@ def get_request_handler(
                         # Merge injected BackgroundTasks with the Response's
                         # own background task so neither set is lost.
                         original = raw_response.background
-                        merged = BackgroundTasks(
-                            solved_result.background_tasks.tasks
-                        )
+                        merged = BackgroundTasks(solved_result.background_tasks.tasks)
                         if isinstance(original, BackgroundTasks):
                             merged.tasks.extend(original.tasks)
                         else:
diff --git a/tests/test_background_tasks_merge.py b/tests/test_background_tasks_merge.py
index 89e640f3ef..3bfff385f4 100644
--- a/tests/test_background_tasks_merge.py
+++ b/tests/test_background_tasks_merge.py
@@ -8,7 +8,7 @@ injected tasks.
 See: https://github.com/fastapi/fastapi/issues/11215
 """
 
-from fastapi import FastAPI, BackgroundTasks
+from fastapi import BackgroundTasks, FastAPI
 from fastapi.testclient import TestClient
 from starlette.background import BackgroundTask
 from starlette.background import BackgroundTasks as StarletteBackgroundTasks