diff --git a/addons/base_calendar/base_calendar.py b/addons/base_calendar/base_calendar.py
index 9421922bb50..eaaa75bbd6e 100644
--- a/addons/base_calendar/base_calendar.py
+++ b/addons/base_calendar/base_calendar.py
@@ -1441,14 +1441,14 @@ true, it will allow you to hide the event alarm information without removing it.
                 data = self.read(cr, uid, event_id, ['date', 'date_deadline', \
                                                     'rrule', 'duration'])
                 if data.get('rrule'):
-                    vals.update(data)
-                    vals.update({
+                    data.update(vals)
+                    data.update({
                         'recurrent_uid': real_event_id,
                         'recurrent_id': data.get('date'),
                         'rrule_type': 'none',
                         'rrule': ''
                         })
-                    new_id = self.copy(cr, uid, real_event_id, default=vals, context=context)
+                    new_id = self.copy(cr, uid, real_event_id, default=data, context=context)
                     context.update({'active_id': new_id, 'active_ids': [new_id]})
                     continue
             if not real_event_id in new_ids: