diff --git a/ua-parser-js/ua-parser-js-tests.ts b/ua-parser-js/ua-parser-js-tests.ts
index 02ddf1403..7ff2c5db5 100644
--- a/ua-parser-js/ua-parser-js-tests.ts
+++ b/ua-parser-js/ua-parser-js-tests.ts
@@ -1,6 +1,8 @@
 /// <reference path='ua-parser-js.d.ts' />
 
-function test_parser(){
+import {UAParser} from 'ua-parser-js';
+
+function test_parser() {
     var ua = 'Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.6 (KHTML, like Gecko) Chrome/20.0.1090.0 Safari/536.6';
     var parser = new UAParser(ua);
     var result = parser.getResult();
@@ -41,4 +43,9 @@ function test_parser(){
     result.cpu.architecture
     parser.getCPU().architecture
 
+    // Extensions
+    var uaString = 'ownbrowser/1.3';
+    var ownBrowser = [[/(ownbrowser)\/([\w\.]+)/i], [UAParser.BROWSER.NAME, UAParser.BROWSER.VERSION]];
+    var parser = new UAParser(uaString, { browser: ownBrowser });
+
 }