diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index 66dc51d1..6fcdb3c3 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -886,7 +886,11 @@ class calendar_ui
 
   function event_rsvp_buttons($attrib = array())
   {
-    return $this->cal->itip->itip_rsvp_buttons($attrib);
+    $actions = array('accepted','tentative','declined');
+    if ($attrib['delegate'] !== 'false')
+      $actions[] = 'delegated';
+
+    return $this->cal->itip->itip_rsvp_buttons($attrib, $actions);
   }
 
 }
diff --git a/plugins/calendar/skins/classic/templates/itipattend.html b/plugins/calendar/skins/classic/templates/itipattend.html
index 84968b58..f4290d82 100644
--- a/plugins/calendar/skins/classic/templates/itipattend.html
+++ b/plugins/calendar/skins/classic/templates/itipattend.html
@@ -13,7 +13,7 @@
 <div class="centerbox">
 	<roundcube:object name="plugin.event_inviteform" />
 	<roundcube:object name="plugin.event_invitebox" class="calendar-invitebox" />
-	<roundcube:object name="plugin.event_rsvp_buttons" type="submit" iname="rsvp" id="event-rsvp" />
+	<roundcube:object name="plugin.event_rsvp_buttons" type="submit" iname="rsvp" id="event-rsvp" delegate="false" />
 	</form>
 </div>
 
diff --git a/plugins/calendar/skins/larry/templates/itipattend.html b/plugins/calendar/skins/larry/templates/itipattend.html
index 0ca14ff8..545d0189 100644
--- a/plugins/calendar/skins/larry/templates/itipattend.html
+++ b/plugins/calendar/skins/larry/templates/itipattend.html
@@ -25,7 +25,7 @@
 <div class="centerbox uibox">
 	<roundcube:object name="plugin.event_inviteform" />
 	<roundcube:object name="plugin.event_invitebox" class="calendar-invitebox" />
-	<roundcube:object name="plugin.event_rsvp_buttons" type="submit" iname="rsvp" id="event-rsvp" />
+	<roundcube:object name="plugin.event_rsvp_buttons" type="submit" iname="rsvp" id="event-rsvp" delegate="false" />
 	</form>
 </div>