diff --git a/webapp/Dockerfile b/webapp/Dockerfile
index 14835c86..d66efe63 100644
--- a/webapp/Dockerfile
+++ b/webapp/Dockerfile
@@ -42,7 +42,7 @@ RUN cat public/silent-check-sso.html <<EOF
 <html>
   <body>
     <script>
-      parent.postMessage(location.href, '${KEYCLOAK_URL}');
+      parent.postMessage(location.href, '*');
     </script>
   </body>
 </html>
