diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 40997764..10d65217 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -523,7 +523,7 @@ function rcube_calendar_ui(settings)
       
       // show warning if editing a recurring event
       if (event.id && event.recurrence) {
-        var sel = event.thisandfuture ? 'future' : 'all';
+        var sel = event.thisandfuture ? 'future' : (event.isexception ? 'current' : 'all');
         $('#edit-recurring-warning').show();
         $('input.edit-recurring-savemode[value="'+sel+'"]').prop('checked', true);
       }
diff --git a/plugins/calendar/drivers/kolab/kolab_calendar.php b/plugins/calendar/drivers/kolab/kolab_calendar.php
index 764f619f..98041c8f 100644
--- a/plugins/calendar/drivers/kolab/kolab_calendar.php
+++ b/plugins/calendar/drivers/kolab/kolab_calendar.php
@@ -434,6 +434,7 @@ class kolab_calendar
         $rec_event['recurrence_id'] = $event['uid'];
         $rec_event['recurrence'] = $recurrence_rule;
         $rec_event['_instance'] = $i;
+        $rec_event['isexception'] = 1;
         $events[] = $rec_event;
 
         // found the specifically requested instance, exiting...