diff --git a/weed/server/volume_server_handlers.go b/weed/server/volume_server_handlers.go
index ef37b48f5..293f36f14 100644
--- a/weed/server/volume_server_handlers.go
+++ b/weed/server/volume_server_handlers.go
@@ -79,7 +79,9 @@ func (vs *VolumeServer) privateStoreHandler(w http.ResponseWriter, r *http.Reque
 		atomic.AddInt64(&vs.inFlightUploadDataSize, contentLength)
 		defer func() {
 			atomic.AddInt64(&vs.inFlightUploadDataSize, -contentLength)
-			vs.inFlightUploadDataLimitCond.Signal()
+			if vs.concurrentUploadLimit != 0 {
+				vs.inFlightUploadDataLimitCond.Signal()
+			}
 		}()
 
 		// processs uploads