diff --git a/nonebot/plugin.py b/nonebot/plugin.py
index 7bb8716f..dd992f57 100644
--- a/nonebot/plugin.py
+++ b/nonebot/plugin.py
@@ -421,10 +421,10 @@ def on_command(cmd: Union[str, Tuple[str, ...]],
     """
 
     async def _strip_cmd(bot: "Bot", event: "Event", state: T_State):
-        message: Iterable[MessageSegment] = event.get_message()
+        message = event.get_message()
         text_processed = False
         for index, segment in enumerate(message):
-            segment: MessageSegment = message.pop(index)
+            segment: "MessageSegment" = message.pop(index)
             if segment.is_text() and not text_processed:
                 segment, *_ = message.__class__(
                     str(segment)[len(state["_prefix"]["raw_command"]):].lstrip(
diff --git a/nonebot/rule.py b/nonebot/rule.py
index 002622a8..45146ae8 100644
--- a/nonebot/rule.py
+++ b/nonebot/rule.py
@@ -137,7 +137,7 @@ class TrieRule:
         prefix = None
         suffix = None
         message = event.get_message()
-        message_seg: Optional[MessageSegment] = next(
+        message_seg: Optional["MessageSegment"] = next(
             filter(lambda x: x.is_text(), message), None)
         if message_seg is not None:
             prefix = cls.prefix.longest_prefix(str(message_seg).lstrip())