diff --git a/src/static/js/ace2_inner.js b/src/static/js/ace2_inner.js
index 34cfba1e4..07580faa5 100644
--- a/src/static/js/ace2_inner.js
+++ b/src/static/js/ace2_inner.js
@@ -3515,7 +3515,11 @@ function Ace2Inner(){
     var which = evt.which;
 
     // prevent ESC key
-    if (keyCode == 27) return;
+    if (keyCode == 27)
+    {
+      evt.preventDefault();
+      return;
+    }
 
     //dmesg("keyevent type: "+type+", which: "+which);
     // Don't take action based on modifier keys going up and down.