diff --git a/jquerymobile/jquerymobile-tests.ts b/jquerymobile/jquerymobile-tests.ts
index 19231849f..b28d308a0 100644
--- a/jquerymobile/jquerymobile-tests.ts
+++ b/jquerymobile/jquerymobile-tests.ts
@@ -71,7 +71,7 @@ function test_pagesDialogs() {
         }
     });
 
-    $(document).bind("pagebeforechange", function (e, data) {
+    $(document).bind("pagebeforechange", function (e, data?) {
         if (typeof data.toPage === "string") {
             var u = $.mobile.path.parseUrl(data.toPage),
                 re = /^#category-item/;