diff --git a/src/phase_plane_widget/static/widget.js b/src/phase_plane_widget/static/widget.js
index 38b775f..fb376e7 100644
--- a/src/phase_plane_widget/static/widget.js
+++ b/src/phase_plane_widget/static/widget.js
@@ -967,3 +967,6 @@ export function render({ model, el }) {
     // cleanup if needed
   };
 }
+
+// Explicit default export for stricter module loaders (marimo)
+export default { render };