diff --git a/core/group_instant.go b/core/group_instant.go
index 7cd3bda..734ac92 100644
--- a/core/group_instant.go
+++ b/core/group_instant.go
@@ -206,6 +206,7 @@ func (gi *groupInstant) Join(w http.ResponseWriter, r *http.Request) {
 		})
 
 		gi.enterRoom(gid, mid)
+		gi.rh.JSONSet(mid.Hex(), "$.instant", bson.M{"id": gd.strid()})
 
 		// 최초 입장이라면 새 멤버에 그룹 전체를 알림
 		gi.sendUpstreamMessage(&wshandler.UpstreamMessage{
@@ -292,7 +293,7 @@ func (gi *groupInstant) Leave(w http.ResponseWriter, r *http.Request) {
 	// mid한테는 빈 GroupDocFull을 보낸다. 그러면 지워짐
 	gi.sendUpstreamMessage(&wshandler.UpstreamMessage{
 		Target: data.Mid.Hex(),
-		Body:   bson.M{"gid": data.Gid},
+		Body:   bson.M{"_gid": data.Gid},
 		Tag:    []string{"GroupDocFull", gd.strid()},
 	})