diff --git a/aiogram/utils/handlers_in_use.py b/aiogram/utils/handlers_in_use.py
index 925870f5..b50e89fa 100644
--- a/aiogram/utils/handlers_in_use.py
+++ b/aiogram/utils/handlers_in_use.py
@@ -3,7 +3,8 @@ from itertools import chain
 from typing import List
 from aiogram.dispatcher.dispatcher import Dispatcher
 
-AIOGRAM_INTERNAL_HANDLERS = ['update', 'error',]
+AIOGRAM_INTERNAL_HANDLERS = ['update', 'error', ]
+
 
 def get_handlers_in_use(dispatcher: Dispatcher, handlers_to_skip: List[str] = AIOGRAM_INTERNAL_HANDLERS) -> List[str]:
     handlers_in_use = []
@@ -14,6 +15,7 @@ def get_handlers_in_use(dispatcher: Dispatcher, handlers_to_skip: List[str] = AI
                 handlers_in_use.extend(chain(*list(map(get_handlers_in_use, router))))
         else:
             for update_name, observer in router.observers.items():
-                if (observer.handlers and update_name not in [*handlers_to_skip, *handlers_in_use]): handlers_in_use.append(update_name)
+                if (observer.handlers and update_name not in [*handlers_to_skip, *handlers_in_use]):
+                    handlers_in_use.append(update_name)
 
     return handlers_in_use