From 0bc9ca62b10571666b12d427fe176ffe571bd617 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Fri, 21 Jun 2019 13:24:08 +0200
Subject: [PATCH] use isArray check

---
 src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 4ee289bd..435594db 100644
--- a/src/index.js
+++ b/src/index.js
@@ -95,7 +95,7 @@ module.exports = (
 
   const externalMap = new Map();
 
-  if (externals instanceof Array)
+  if (Array.isArray(externals))
     externals.forEach(external => externalMap.set(external, external));
   else if (typeof externals === 'object')
     Object.keys(externals).forEach(external => externalMap.set(external, externals[external]));