1 files changed, 7 insertions, 5 deletions
diff --git a/node_modules/core-js/modules/es6.weak-set.js b/node_modules/core-js/modules/es6.weak-set.js
index 77d01b6ba..18a81e524 100644
--- a/node_modules/core-js/modules/es6.weak-set.js
+++ b/node_modules/core-js/modules/es6.weak-set.js
@@ -1,12 +1,14 @@
 'use strict';
 var weak = require('./_collection-weak');
+var validate = require('./_validate-collection');
+var WEAK_SET = 'WeakSet';
 
 // 23.4 WeakSet Objects
-require('./_collection')('WeakSet', function(get){
-  return function WeakSet(){ return get(this, arguments.length > 0 ? arguments[0] : undefined); };
+require('./_collection')(WEAK_SET, function (get) {
+  return function WeakSet() { return get(this, arguments.length > 0 ? arguments[0] : undefined); };
 }, {
   // 23.4.3.1 WeakSet.prototype.add(value)
-  add: function add(value){
-    return weak.def(this, value, true);
+  add: function add(value) {
+    return weak.def(validate(this, WEAK_SET), value, true);
   }
-}, weak, false, true);
-\ No newline at end of file
+}, weak, false, true);