diff --git a/lib/6to5/transformation/transformer.js b/lib/6to5/transformation/transformer.js
index d9587a38c0..f4de701b51 100644
--- a/lib/6to5/transformation/transformer.js
+++ b/lib/6to5/transformation/transformer.js
@@ -65,7 +65,7 @@ Transformer.prototype.transform = function (file) {
       if (exit) fn = fns.exit;
       if (!fn) return;
 
-      return fn(node, parent, file, scope);
+      return fn.call(this, node, parent, file, scope);
     };
   };