diff --git a/js/ui/overlay.js b/js/ui/overlay.js
index 894d3c6ba..14e69afe3 100644
--- a/js/ui/overlay.js
+++ b/js/ui/overlay.js
@@ -92,6 +92,7 @@ Overlay.prototype = {
         this._group._delegate = this;
 
         this.visible = false;
+        this.animationInProgress = false;
         this._hideInProgress = false;
 
         this._recalculateGridSizes();
@@ -242,6 +243,7 @@ Overlay.prototype = {
             return;
 
         this.visible = true;
+        this.animationInProgress = true;
 
         let global = Shell.Global.get();
         let screenWidth = global.screen_width;
@@ -309,6 +311,7 @@ Overlay.prototype = {
 
         let global = Shell.Global.get();
 
+        this.animationInProgress = true;
         this._hideInProgress = true;
         if (this._activeDisplayPane != null)
             this._activeDisplayPane.close();
@@ -377,6 +380,8 @@ Overlay.prototype = {
         this._dash.actor.raise_top();
         this._dash.actor.remove_clip();
 
+        this.animationInProgress = false;
+
         this.emit('shown');
     },
 
@@ -393,6 +398,7 @@ Overlay.prototype = {
         this._group.hide();
 
         this.visible = false; 
+        this.animationInProgress = false;
         this._hideInProgress = false;
 
         Main.endModal();
diff --git a/js/ui/panel.js b/js/ui/panel.js
index d8ac1ac6e..13d532052 100644
--- a/js/ui/panel.js
+++ b/js/ui/panel.js
@@ -83,8 +83,7 @@ Panel.prototype = {
 
         // In addition to being triggered by the mouse enter event, the hot corner
         // can be triggered by clicking on it. This is useful if the user wants to 
-        // immediately undo the effect of triggering the hot corner once in the 
-        // hot corner.
+        // undo the effect of triggering the hot corner once in the hot corner.
         hotCorner.connect('enter-event',
                            Lang.bind(this, this._onHotCornerTriggered));
         hotCorner.connect('button-release-event',
@@ -220,7 +219,9 @@ Panel.prototype = {
     },
 
     _onHotCornerTriggered : function() {
-        Main.overlay.toggle();
+        if (!Main.overlay.animationInProgress) {
+            Main.overlay.toggle();
+        }
         return false;
      }
 };