diff --git a/livekit-rtc/livekit/rtc/room.py b/livekit-rtc/livekit/rtc/room.py
index aeeb3da7..6ca1cfb3 100644
--- a/livekit-rtc/livekit/rtc/room.py
+++ b/livekit-rtc/livekit/rtc/room.py
@@ -455,7 +455,7 @@ def _retrieve_remote_participant(
             participant = self.participants[sid]
         return participant
 
-    def _retrieve_participant(self, sid: str, identity: str) -> Participant:
+    def _retrieve_participant(self, sid: str, identity: str) -> Optional[Participant]:
         """Retrieve a participant by sid or identity,
         returns the LocalParticipant if sid or identity matches"""
         if identity and identity == self.local_participant.identity: