diff --git a/biz/master/client/update_tunnel.go b/biz/master/client/update_tunnel.go
index 4374c9b..a8b2040 100644
--- a/biz/master/client/update_tunnel.go
+++ b/biz/master/client/update_tunnel.go
@@ -85,7 +85,9 @@ func UpdateFrpcHander(c context.Context, req *pb.UpdateFRPCRequest) (*pb.UpdateF
 
 	cli.ConfigContent = rawCliConf
 	cli.ServerID = serverID
-	cli.Comment = req.GetComment()
+	if req.Comment != nil {
+		cli.Comment = req.GetComment()
+	}
 
 	if err := dao.UpdateClient(userInfo, cli); err != nil {
 		logrus.WithError(err).Errorf("cannot update client, id: [%s]", clientID)