diff --git a/addons/calendar/security/ir.model.access.csv b/addons/calendar/security/ir.model.access.csv
index 07065a19e96..48e529ade2d 100644
--- a/addons/calendar/security/ir.model.access.csv
+++ b/addons/calendar/security/ir.model.access.csv
@@ -1,5 +1,5 @@
 id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
-access_calendar_attendee_portal,calendar.attendee_portal,model_calendar_attendee,base.group_portal,1,1,0,0
+access_calendar_attendee_portal,calendar.attendee_portal,model_calendar_attendee,base.group_portal,0,0,0,0
 access_calendar_attendee_employee,calendar.attendee_employee,model_calendar_attendee,base.group_user,1,1,1,1
 access_calendar_alarm,calendar.alarm,model_calendar_alarm,base.group_user,1,1,1,1
 access_calendar_event_all_user,calendar.event_all_user,model_calendar_event,base.group_portal,1,0,0,0