diff --git a/src/calendar.js b/src/calendar.js
index 0b112c0..4f5fe8f 100644
--- a/src/calendar.js
+++ b/src/calendar.js
@@ -289,8 +289,8 @@ angular.module('ui.calendar', [])
         };
 
         eventsWatcher.onChanged = function(event) {
-          event._start = $.fullCalendar.moment(event.start);
-          event._end = $.fullCalendar.moment(event.end);
+          event._start = jQuery.fullCalendar.moment(event.start);
+          event._end = jQuery.fullCalendar.moment(event.end);
           calendar.fullCalendar('updateEvent', event);
         };