diff --git a/js/ui/layout.js b/js/ui/layout.js
index 8f08d3768..e615e566e 100644
--- a/js/ui/layout.js
+++ b/js/ui/layout.js
@@ -558,6 +558,8 @@ var LayoutManager = new Lang.Class({
     },
 
     get focusMonitor() {
+        if (this.focusIndex < 0)
+            return null;
         return this.monitors[this.focusIndex];
     },