diff --git a/weed/server/master_grpc_server.go b/weed/server/master_grpc_server.go
index 0cdcd33cb..4d0fbbc41 100644
--- a/weed/server/master_grpc_server.go
+++ b/weed/server/master_grpc_server.go
@@ -113,7 +113,7 @@ func (ms *MasterServer) SendHeartbeat(stream master_pb.Seaweed_SendHeartbeatServ
 			uuidlist, err := ms.RegisterUuids(heartbeat)
 			if err != nil {
 				if stream_err := stream.Send(&master_pb.HeartbeatResponse{
-					DuplicatedUuids:    uuidlist,
+					DuplicatedUuids: uuidlist,
 				}); stream_err != nil {
 					glog.Warningf("SendHeartbeat.Send DuplicatedDirectory response to %s:%d %v", dn.Ip, dn.Port, stream_err)
 					return stream_err