diff --git a/sumorobot.js b/sumorobot.js
index 36d7933..cd34224 100755
--- a/sumorobot.js
+++ b/sumorobot.js
@@ -429,8 +429,8 @@ window.onload = function() {
         block_highlight = new WebSocket("ws://" + robotServer + ":80/p2p/browser/" + robotID + "-highlight/");
         /* when there is a message from the WebSocket */
         block_highlight.onmessage = function(evt) {
-            /* when scope is received */
-            if (evt.data.length == 20) {
+            /* when block id received and sumorobot is started */
+            if (evt.data.length == 20 && sumostart) {
                 workspace.highlightBlock(evt.data);
                 highlighted = evt.data;
             }