Index: res/res_calendar.c
===================================================================
--- res/res_calendar.c	(revision 391701)
+++ res/res_calendar.c	(working copy)
@@ -1819,6 +1819,8 @@
 
 	/* Remove all calendars */
 	ao2_callback(calendars, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
+	ao2_cleanup(calendars);
+	calendars = NULL;
 
 	ast_mutex_lock(&refreshlock);
 	module_unloading = 1;