diff --git a/syncapi/streams/stream_pdu.go b/syncapi/streams/stream_pdu.go
index 8215e0977..d23209af3 100644
--- a/syncapi/streams/stream_pdu.go
+++ b/syncapi/streams/stream_pdu.go
@@ -255,7 +255,7 @@ func (p *PDUStreamProvider) addRoomDeltaToResponse(
 
 	hasMembershipChange := false
 	for _, recentEvent := range recentStreamEvents {
-		if recentEvent.Type() == gomatrixserverlib.MRoomMember {
+		if recentEvent.Type() == gomatrixserverlib.MRoomMember && recentEvent.StateKey() != nil {
 			hasMembershipChange = true
 			break
 		}