From 12f68b05c3fcebf3f4c15f68cbdeabb6c5527a14 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Fri, 7 Nov 2014 12:27:57 +1100
Subject: [PATCH] better Symbol polyfill existence check because the one
 es6-symbol uses isn't reliable

---
 lib/6to5/polyfill.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/6to5/polyfill.js b/lib/6to5/polyfill.js
index 221aa97a57..12a9db8bb7 100644
--- a/lib/6to5/polyfill.js
+++ b/lib/6to5/polyfill.js
@@ -1,3 +1,6 @@
-require("es6-symbol/implement");
+if (typeof Symbol === "undefined") {
+  require("es6-symbol/implement");
+}
+
 require("es6-shim");
 require("regenerator/runtime");