diff --git a/attachment_preview/static/src/js/attachment_preview.js b/attachment_preview/static/src/js/attachment_preview.js
index 7bc400e3..1fe7e699 100644
--- a/attachment_preview/static/src/js/attachment_preview.js
+++ b/attachment_preview/static/src/js/attachment_preview.js
@@ -26,7 +26,7 @@ openerp.attachment_preview = function(instance)
             attachment_id, attachment_url, attachment_extension,
             attachment_title)
     {
-        var url = window.location.origin +
+        var url = (window.location.origin || '') +
             '/attachment_preview/static/lib/ViewerJS/index.html#' +
             attachment_url.replace(window.location.origin, '') +
             '&title=' + encodeURIComponent(attachment_title) +