diff --git a/mirai_onebot/api/interfaces/group.py b/mirai_onebot/api/interfaces/group.py
index 0aea6c7..698522f 100644
--- a/mirai_onebot/api/interfaces/group.py
+++ b/mirai_onebot/api/interfaces/group.py
@@ -1,3 +1,5 @@
+from typing import List
+
 from mirai_onebot.api.interfaces.base import (Request, RequestParams, Response,
                                               ResponseData)
 
@@ -28,7 +30,7 @@ class GetGroupListRequestParams(RequestParams):
 
 
 class GetGroupListResponseData(ResponseData):
-    group_list: list[GetGroupInfoResponseData]
+    group_list: List[GetGroupInfoResponseData]
 
 
 class GetGroupListRequest(Request):
@@ -69,7 +71,7 @@ class GetGroupMemberListRequestParams(RequestParams):
 
 
 class GetGroupMemberListResponseData(ResponseData):
-    member_list: list[GetGroupMemberInfoResponseData]
+    member_list: List[GetGroupMemberInfoResponseData]
 
 
 class GetGroupMemberListRequest(Request):
diff --git a/mirai_onebot/event/bus.py b/mirai_onebot/event/bus.py
index 6fbc137..5a50f0d 100644
--- a/mirai_onebot/event/bus.py
+++ b/mirai_onebot/event/bus.py
@@ -47,7 +47,7 @@ def decorator(func: Callable) -> Callable:
 
         return decorator
 
-    async def emit(self, event: Union[Type[EventBase], str], background: bool = True, *args, **kwargs) -> None:
+    async def emit(self, event: Union[Type[EventBase], str], *args, **kwargs) -> None:
         """触发事件
 
         Args:
@@ -58,5 +58,5 @@ async def emit(self, event: Union[Type[EventBase], str], background: bool = True
         if event in self._subscribers.keys():
             tasks = [asyncio.create_task(subscriber(*args, **kwargs))
                      for subscriber in self._subscribers[event]]
-            if not background:
+            if kwargs.get('background', True) is False:
                 await asyncio.wait(tasks)