diff --git a/sumorobot.js b/sumorobot.js
index 0745b59..760265b 100755
--- a/sumorobot.js
+++ b/sumorobot.js
@@ -265,6 +265,8 @@ window.onload = function() {
 
     /* on blockly code change */
     function onCodeChanged(event) {
+        /* only process change and move commands */
+        if (event.type != Blockly.Events.CHANGE && event.type != Blockly.Events.MOVE) return;
         /* generate code from the used blocks */
         var code = Blockly.Sumorobot.workspaceToCode(workspace);