diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index dc1a8474..d9bfb300 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -225,7 +225,7 @@ class calendar extends rcube_plugin
     // initialize attendees autocompletion
     rcube_autocomplete_init();
 
-    $this->rc->output->set_env('calendar.driver', $this->rc->config->get('calendar_driver'), false);
+    $this->rc->output->set_env('calendar_driver', $this->rc->config->get('calendar_driver'), false);
 
     $this->rc->output->send("calendar.calendar");
   }
diff --git a/plugins/calendar/skins/default/templates/calendar.html b/plugins/calendar/skins/default/templates/calendar.html
index 066c2b20..6b5e6f68 100644
--- a/plugins/calendar/skins/default/templates/calendar.html
+++ b/plugins/calendar/skins/default/templates/calendar.html
@@ -33,7 +33,7 @@
   <ul>
     <li><roundcube:button command="calendar-edit" label="calendar.edit" classAct="active" /></li>
     <li><roundcube:button command="calendar-remove" label="calendar.remove" classAct="active" /></li>
-    <roundcube:if condition="env:calendar.driver == 'kolab'" />
+    <roundcube:if condition="env:calendar_driver == 'kolab'" />
     <li class="separator_above"><roundcube:button command="folders" task="settings" type="link" label="managefolders" classAct="active" /></li>
     <roundcube:endif />
   </ul>