diff --git a/ui/core.js b/ui/core.js
index ee01d5988..0b2e03950 100644
--- a/ui/core.js
+++ b/ui/core.js
@@ -97,7 +97,7 @@ function focusable( element, isTabIndexNotNaN ) {
 		img = $( "img[usemap='#" + mapName + "']" )[ 0 ];
 		return !!img && visible( img );
 	}
-	return ( /input|select|textarea|button|object/.test( nodeName ) ?
+	return ( /^(input|select|textarea|button|object)$/.test( nodeName ) ?
 		!element.disabled :
 		"a" === nodeName ?
 			element.href || isTabIndexNotNaN :