diff --git a/modules/browserUIShowHideObserver.js b/modules/browserUIShowHideObserver.js
index 019c1a0b..096e2327 100644
--- a/modules/browserUIShowHideObserver.js
+++ b/modules/browserUIShowHideObserver.js
@@ -65,7 +65,9 @@ BrowserUIShowHideObserver.prototype = {
 				'hidden',
 				'collapsed',
 				'moz-collapsed', // Used in full screen mode
-				'disablechrome'
+				'disablechrome',
+				'width',
+				'height'
 			]
 		});
 	},