diff --git a/.config/init.ml b/.config/init.ml
index 33c1702..158f505 100644
--- a/.config/init.ml
+++ b/.config/init.ml
@@ -59,7 +59,9 @@ let setup_workspace ~container cstore : unit Lwt.t =
                (Headers.get headers "path"))
         in
         let status = F.str "Name: %s; Path: %a" step Uri.pp_hum uri in
-        let window = Tyxml_js.Html.[ "window" ] in
+        let window : Html_types.nmtokens =
+          Tyxml_js.Html.[ "window" ]
+        in
         appendchild ~container
           Tyxml_js.Html.(
             a