diff --git a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
index 67baa4ce..9a37df03 100644
--- a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
+++ b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
@@ -809,6 +809,17 @@ class tasklist_kolab_driver extends tasklist_driver
             $task['alarms'] = $record['alarms'];
         }
 
+        if (!empty($task['attendees'])) {
+            foreach ((array)$task['attendees'] as $i => $attendee) {
+                if (is_array($attendee['delegated-from'])) {
+                    $task['attendees'][$i]['delegated-from'] = join(', ', $attendee['delegated-from']);
+                }
+                if (is_array($attendee['delegated-to'])) {
+                    $task['attendees'][$i]['delegated-to'] = join(', ', $attendee['delegated-to']);
+                }
+            }
+        }
+
         if (!empty($record['_attachments'])) {
             foreach ($record['_attachments'] as $key => $attachment) {
                 if ($attachment !== false) {
diff --git a/plugins/tasklist/tasklist.js b/plugins/tasklist/tasklist.js
index 4c07937c..ff80731a 100644
--- a/plugins/tasklist/tasklist.js
+++ b/plugins/tasklist/tasklist.js
@@ -1830,7 +1830,7 @@ function rcube_tasklist_ui(settings)
             $('#task-rsvp .itip-reply-comment textarea').hide().val('');
 
             if (rec.organizer && !organizer) {
-                $('#task-organizer').show().children('.task-text').html(task_attendee_html(rec.organizer));
+                $('#task-organizer').show().children('.task-text').html(task_attendee_html($.extend(rec.organizer, { role:'ORGANIZER' })));
             }
         }