diff --git a/client/index_template.html b/client/index_template.html
index fabe219f..07c5678a 100644
--- a/client/index_template.html
+++ b/client/index_template.html
@@ -39,7 +39,7 @@
     <script type="text/javascript">
       window.CELLXGENE = {};
       window.CELLXGENE.API = {
-        prefix: window.location.href + "api/",
+        prefix: `${location.origin}${location.pathname}api/`,
         version: "v0.2/",
       };
     </script>