diff --git a/lib/register.js b/lib/register.js
index 52963a93..69568c9b 100644
--- a/lib/register.js
+++ b/lib/register.js
@@ -429,7 +429,7 @@ function createEntry() {
       entry.esModule = loader.newModule(getESModule(exports));
     // just use the 'default' export
     else
-      entry.esModule = loader.newModule({ 'default': exports });
+      entry.esModule = loader.newModule({ 'default': exports, __useDefault: true });
   }
 
   /*