diff --git a/index.js b/index.js
index 521e828..f02edeb 100644
--- a/index.js
+++ b/index.js
@@ -183,7 +183,7 @@
     USPProto.keys = USPProto.keys || function() {
         var items = [];
         this.forEach(function(item, name) {
-            items.push([name]);
+            items.push(name);
         });
         return makeIterator(items);
     };
@@ -197,7 +197,7 @@
     USPProto.values = USPProto.values || function() {
         var items = [];
         this.forEach(function(item) {
-            items.push([item]);
+            items.push(item);
         });
         return makeIterator(items);
     };
diff --git a/package.json b/package.json
index 6dce230..191df29 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "url-search-params-polyfill",
-  "version": "3.0.0",
+  "version": "4.0.0",
   "description": "a simple polyfill for javascript URLSearchParams",
   "homepage": "https://github.com/jerrybendy/url-search-params-polyfill",
   "main": "index.js",
diff --git a/test/index.test.js b/test/index.test.js
index 9f0f801..5e2d6d4 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -228,6 +228,8 @@ describe(PREFIX + 'Iterator', function () {
             ret.push(key);
         }
         expect(ret.join(';')).to.be.equal('a;b;c');
+
+        expect(Array.from(obj.keys())).to.be.eql(['a','b','c']);
     });
 
     it('values', function () {
@@ -237,6 +239,8 @@ describe(PREFIX + 'Iterator', function () {
             ret.push(value);
         }
         expect(ret.join(';')).to.be.equal('1;2;3');
+
+        expect(Array.from(obj.values())).to.be.eql(['1', '2', '3']);
     });
 
 });