diff --git a/js/jquery.mobile.navigation.js b/js/jquery.mobile.navigation.js
index 478d06f4..2bd09252 100644
--- a/js/jquery.mobile.navigation.js
+++ b/js/jquery.mobile.navigation.js
@@ -171,7 +171,7 @@
 		}
 
 		//base element management, defined depending on dynamic base tag support
-		base = $.support.dynamicBaseTag ? {
+		var base = $.support.dynamicBaseTag ? {
 
 			//define base element, for use in routing asset urls that are referenced in Ajax-requested markup
 			element: ($base.length ? $base : $("<base>", { href: docBase }).prependTo( $head )),