From c87b72f2ff7f65e708c4b59a752ef234d0f28d1f Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Mon, 25 Sep 2017 18:29:54 -0400
Subject: [PATCH] fix: allow installation on extended Vue copies

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

diff --git a/src/store.js b/src/store.js
index 0a540e809..7f479a29d 100644
--- a/src/store.js
+++ b/src/store.js
@@ -459,7 +459,7 @@ function unifyObjectStyle (type, payload, options) {
 }
 
 export function install (_Vue) {
-  if (Vue) {
+  if (Vue && _Vue === Vue) {
     if (process.env.NODE_ENV !== 'production') {
       console.error(
         '[vuex] already installed. Vue.use(Vuex) should be called only once.'