diff --git a/plugins/calendar/drivers/kolab/kolab_calendar.php b/plugins/calendar/drivers/kolab/kolab_calendar.php
index 9eb70bdc..9427b1c7 100644
--- a/plugins/calendar/drivers/kolab/kolab_calendar.php
+++ b/plugins/calendar/drivers/kolab/kolab_calendar.php
@@ -267,9 +267,18 @@ class kolab_calendar
         $add = true;
 
         // skip the first instance of a recurring event if listed in exdate
-        if ($virtual && !empty($event['recurrence']['EXDATE'])) {
+        if ($virtual && (!empty($event['recurrence']['EXDATE']) || !empty($event['recurrence']['EXCEPTIONS']))) {
           $event_date = $event['start']->format('Ymd');
-          foreach ($event['recurrence']['EXDATE'] as $exdate) {
+          $exdates = (array)$event['recurrence']['EXDATE'];
+
+          // add dates from exceptions to list
+          if (is_array($event['recurrence']['EXCEPTIONS'])) {
+              foreach ($event['recurrence']['EXCEPTIONS'] as $exception) {
+                  $exdates[] = clone $exception['start'];
+              }
+          }
+
+          foreach ($exdates as $exdate) {
             if ($exdate->format('Ymd') == $event_date) {
               $add = false;
               break;