diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 45a537f4..345599bf 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -322,7 +322,8 @@ function rcube_calendar_ui(settings)
         }
       }
 
-      rcmail.goto_url('get-attachment', qstring+'&_download=1', false);
+      query._frame = null;
+      rcmail.goto_url('get-attachment', query, false);
     };
 
     // build event attachments list