diff --git a/lib/6to5/register.js b/lib/6to5/register.js
index efdec2ad90..b8203ae462 100644
--- a/lib/6to5/register.js
+++ b/lib/6to5/register.js
@@ -89,7 +89,6 @@ var loader = function (m, filename) {
     whitelist: whitelist,
     blacklist: blacklist,
     sourceMap: true,
-    modules:   "commonInterop",
     ast:       false
   }, transformOpts));