diff --git a/demo/fullcalendar/demofullcalendar.lpr b/demo/fullcalendar/demofullcalendar.lpr
index 97a4be1..07d8d54 100644
--- a/demo/fullcalendar/demofullcalendar.lpr
+++ b/demo/fullcalendar/demofullcalendar.lpr
@@ -3,7 +3,7 @@ program demofullcalendar;
 {$mode objfpc}
 
 uses
-  dateutils, browserapp, JS, Classes, SysUtils, Web, libfullcalendar;
+  dateutils, browserapp, types, JS, Classes, SysUtils, Web, libfullcalendar4;
 
 type