diff --git a/og_context/js/og_context.ajax.js b/og_context/js/og_context.ajax.js
index a5eeb2d..b252a60 100644
--- a/og_context/js/og_context.ajax.js
+++ b/og_context/js/og_context.ajax.js
@@ -25,7 +25,7 @@ Drupal.behaviors.ogContext = {
 
         // Modify the Ajax request URL to add the GET variable, but only if the
         // request is being made to a URL on this site.
-        if (Drupal.urlIsLocal(settings.url)) {
+        if (typeof settings.url !== 'undefined' && Drupal.urlIsLocal(settings.url)) {
           settings.url += settings.url.indexOf('?') >= 0 ? '&' : '?';
           settings.url += 'og_ajax_context__gid=' + Drupal.settings.ogContext.gid + '&og_ajax_context__group_type=' + Drupal.settings.ogContext.groupType;
         }