diff --git a/nonebot/adapters/cqhttp/bot.py b/nonebot/adapters/cqhttp/bot.py
index a96f1308..d0f90dd7 100644
--- a/nonebot/adapters/cqhttp/bot.py
+++ b/nonebot/adapters/cqhttp/bot.py
@@ -302,7 +302,7 @@ class Bot(BaseBot):
             detail_type = f".{detail_type}" if detail_type else ""
             sub_type = message.get("sub_type")
             sub_type = f".{sub_type}" if sub_type else ""
-            models = get_event_model(f".{post_type}{detail_type}{sub_type}")
+            models = get_event_model(post_type + detail_type + sub_type)
             for model in models:
                 try:
                     event = model.parse_obj(message)
diff --git a/nonebot/adapters/cqhttp/event.py b/nonebot/adapters/cqhttp/event.py
index eaede5d5..0d28101b 100644
--- a/nonebot/adapters/cqhttp/event.py
+++ b/nonebot/adapters/cqhttp/event.py
@@ -237,6 +237,10 @@ class CQHTTPEvent(Event):
     def get_plaintext(self) -> str:
         raise ValueError("Event has no message!")
 
+    @overrides(Event)
+    def get_session_id(self) -> str:
+        raise ValueError("Event has no message!")
+
 
 # Models
 class Sender(BaseModel):
@@ -322,6 +326,10 @@ class MessageEvent(CQHTTPEvent):
     def get_plaintext(self) -> str:
         return self.message.extract_plain_text()
 
+    @overrides(CQHTTPEvent)
+    def get_session_id(self) -> str:
+        return str(self.user_id)
+
 
 class PrivateMessageEvent(MessageEvent):
     __event__ = "message.private"