diff --git a/ckanext-hdx_theme/ckanext/hdx_theme/fanstatic/onboarding/prevent-back-button.js b/ckanext-hdx_theme/ckanext/hdx_theme/fanstatic/onboarding/prevent-back-button.js
index 52715b739d..78e0991439 100644
--- a/ckanext-hdx_theme/ckanext/hdx_theme/fanstatic/onboarding/prevent-back-button.js
+++ b/ckanext-hdx_theme/ckanext/hdx_theme/fanstatic/onboarding/prevent-back-button.js
@@ -6,7 +6,7 @@ window.onpopstate = function (event) {
     if (r === true) {
       history.back();
     } else {
-      window.history.pushState({page: 2}, '', '');
+      window.history.pushState({page: 2}, null, null);
     }
   }
 }