diff --git a/lib/6to5/transformer.js b/lib/6to5/transformer.js
index 78bc05a342..226816cab4 100644
--- a/lib/6to5/transformer.js
+++ b/lib/6to5/transformer.js
@@ -32,10 +32,12 @@ Transformer.prototype.transform = function (file) {
     transformer.ast.enter(ast, file);
   }
 
+  var self = this;
+
   var build = function (exit) {
     return function (node, parent) {
       // add any node type aliases that exist
-      var types = [node.type].concat(t.aliases[node.type] || []);
+      var types = [node.type].concat(t.ALIAS_KEYS[node.type] || []);
 
       var fns = transformer.all;