diff --git a/lib/6to5/traverse/index.js b/lib/6to5/traverse/index.js
index 8e558cbdd5..08a71bb35d 100644
--- a/lib/6to5/traverse/index.js
+++ b/lib/6to5/traverse/index.js
@@ -1,5 +1,4 @@
-var VISITOR_KEYS = require("./visitor-keys");
-var _            = require("lodash");
+var _ = require("lodash");
 
 var traverse = module.exports = function (parent, callbacks, blacklistTypes) {
   // falsy node
@@ -14,7 +13,7 @@ var traverse = module.exports = function (parent, callbacks, blacklistTypes) {
   }
 
   // unknown node type to traverse
-  var keys = VISITOR_KEYS[parent.type];
+  var keys = traverse.VISITOR_KEYS[parent.type];
   if (!keys) return;
 
   // blacklist these node types from being traversed
@@ -72,6 +71,8 @@ var traverse = module.exports = function (parent, callbacks, blacklistTypes) {
   });
 };
 
+traverse.VISITOR_KEYS = require("./visitor-keys");
+
 traverse.removeProperties = function (tree) {
   var clear = function (node) {
     delete node.tokens;