diff --git a/public/javascripts/init.js b/public/javascripts/init.js
index c777b765f..8517163bc 100644
--- a/public/javascripts/init.js
+++ b/public/javascripts/init.js
@@ -116,7 +116,7 @@ function initAjax() {
     $.ajaxSetup({
         headers: {
             'x-browser-id': browserId,
-            'x-protected-session-id': protected_session ? protected_session.getProtectedSessionId() : null
+            'x-protected-session-id': typeof protected_session !== 'undefined' ? protected_session.getProtectedSessionId() : null
         }
     });
 }