diff --git a/calendar/base/modules/Ical.jsm b/calendar/base/modules/Ical.jsm
index b49b3fe724..4f4e5e5b55 100644
--- a/calendar/base/modules/Ical.jsm
+++ b/calendar/base/modules/Ical.jsm
@@ -10,6 +10,7 @@
  *
  * Current ical.js git revision: 7fb7b51f1b36d49b576a359ee178d85e6d4b192a
  * plus https://github.com/kewisch/ical.js/pull/541
+ * plus https://github.com/kewisch/ical.js/pull/531
  */
 
 var EXPORTED_SYMBOLS = ["ICAL", "unwrap", "unwrapSetter", "unwrapSingle", "wrapGetter"];