diff --git a/www/bounce/main.js b/www/bounce/main.js
index 74a0d0154..d2687308d 100644
--- a/www/bounce/main.js
+++ b/www/bounce/main.js
@@ -1,5 +1,5 @@
-define([], function () {
-    if (window.localStorage && window.localStorage.FS_hash) {
+define(['/api/config'], function (ApiConfig) {
+    if (ApiConfig.httpSafeOrigin === window.location.origin) {
         window.alert('The bounce application must only be used from the sandbox domain, ' +
             'please report this issue on https://github.com/xwiki-labs/cryptpad');
         return;