diff --git a/package.json b/package.json
index 31ab415..a92be31 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "title": "UA-Parser.JS",
   "name": "ua-parser-js",
-  "version": "0.4.4",
+  "version": "0.4.5",
   "author": "Faisal Salman <fyzlman@gmail.com> (http://faisalman.com)",
   "description": "Lightweight JavaScript-based user-agent string parser",
   "keywords": [
diff --git a/ua-parser.js b/ua-parser.js
index 82e5a9d..4971222 100644
--- a/ua-parser.js
+++ b/ua-parser.js
@@ -1,4 +1,4 @@
-// UA-Parser.JS v0.4.4
+// UA-Parser.JS v0.4.5
 // Lightweight JavaScript-based User-Agent string parser
 // https://github.com/faisalman/ua-parser-js
 //
@@ -264,10 +264,10 @@
 
     var UAParser = function UAParser (uastring) {
 
-        var ua = uastring || (typeof window !== 'undefined' ? window.navigator.userAgent : "");
+        var ua = uastring || ((window && window.navigator && window.navigator.userAgent) ? window.navigator.userAgent : "");
 
         this.getBrowser = function () {
-            return mapper.regex.apply(this, regexes.browser);  
+            return mapper.regex.apply(this, regexes.browser);
         };
 
         this.getDevice = function () {