From 04c2c547001cd7e1e8f8845ff6f199450f9401b0 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Mon, 3 Aug 2015 02:40:43 +0100
Subject: [PATCH] add exception to non-existent bindings when checking if we
 need to wrap in a closure

---
 .../babel/src/transformation/transformers/es6/block-scoping.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/babel/src/transformation/transformers/es6/block-scoping.js b/packages/babel/src/transformation/transformers/es6/block-scoping.js
index 7f5dc6a18e..a0d61a37e8 100644
--- a/packages/babel/src/transformation/transformers/es6/block-scoping.js
+++ b/packages/babel/src/transformation/transformers/es6/block-scoping.js
@@ -209,7 +209,8 @@ var letReferenceFunctionVisitor = {
 
     // this scope has a variable with the same name so it couldn't belong
     // to our let scope
-    if (scope.getBindingIdentifier(node.name) !== ref) return;
+    var localBinding = scope.getBindingIdentifier(node.name);
+    if (localBinding && localBinding !== ref) return;
 
     state.closurify = true;
   }