diff --git a/lib/index.js b/lib/index.js
index 37ff54b..884ec28 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -26,4 +26,4 @@ u.update = update;
 u.updateIn = updateIn;
 u.withDefault = withDefault;
 
-export default u;
+module.exports = u;