diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 9d460863..86a2d122 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -384,7 +384,7 @@ class calendar extends rcube_plugin
       $input_value = new html_inputfield(array('name' => '_alarm_value', 'id' => $field_id . 'value', 'size' => 3));
       $select_offset = new html_select(array('name' => '_alarm_offset', 'id' => $field_id . 'offset'));
       foreach (array('-M','-H','-D','+M','+H','+D') as $trigger)
-        $select_offset->add($this->gettext('trigger' . $trigger), $trigger);
+        $select_offset->add(rcube_label('trigger' . $trigger, 'libcalendaring'), $trigger);
       
       $p['blocks']['view']['options']['alarmtype'] = array(
         'title' => html::label($field_id, Q($this->gettext('defaultalarmtype'))),