Index: wp-admin/js/customize-nav-menus.js
===================================================================
--- wp-admin/js/customize-nav-menus.js	(revision 40950)
+++ wp-admin/js/customize-nav-menus.js	(working copy)
@@ -537,6 +537,8 @@
 				itemName = $( '#custom-menu-item-name' ),
 				itemUrl = $( '#custom-menu-item-url' );
 
+            var regex = new RegExp("^(http[s]?:\\/\\/(www\\.)?|ftp:\\/\\/(www\\.)?|www\\.){1}([0-9A-Za-z-\\.@:%_\+~#=]+)+((\\.[a-zA-Z]{2,3})+)(/(.)*)?(\\?(.)*)?");
+
 			if ( ! this.currentMenuControl ) {
 				return;
 			}
@@ -544,7 +546,7 @@
 			if ( '' === itemName.val() ) {
 				itemName.addClass( 'invalid' );
 				return;
-			} else if ( '' === itemUrl.val() || 'http://' === itemUrl.val() ) {
+			} else if ( '' === itemUrl.val()  || regex.test(itemUrl.val()) == false ) {
 				itemUrl.addClass( 'invalid' );
 				return;
 			}