diff --git a/SoObjects/Appointments/SOGoAppointmentObject.h b/SoObjects/Appointments/SOGoAppointmentObject.h
index 90f720f98..37f63201b 100644
--- a/SoObjects/Appointments/SOGoAppointmentObject.h
+++ b/SoObjects/Appointments/SOGoAppointmentObject.h
@@ -52,6 +52,7 @@
 
 - (NSArray *) postCalDAVEventRequestTo: (NSArray *) recipients;
 - (NSArray *) postCalDAVEventReplyTo: (NSArray *) recipients;
+- (NSArray *) postCalDAVEventCancelTo: (NSArray *) recipients;
 
 /* "iCal multifolder saves" */