diff --git a/package.json b/package.json
index e4f7043b8..270a725c2 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
     "debug": "^3.1.0",
     "eventsource": "^1.0.5",
     "iconv-lite": "^0.4.21",
-    "jsdom": "11.5.1",
+    "jsdom": "11.12.0",
     "lodash": "^4.17.10",
     "mime": "^2.3.1",
     "ms": "^2.1.1",
diff --git a/src/document.js b/src/document.js
index e49384703..523b915db 100644
--- a/src/document.js
+++ b/src/document.js
@@ -149,7 +149,12 @@ function setupWindow(window, args) {
   window.MouseEvent =     DOM.MouseEvent;
   window.MutationEvent =  DOM.MutationEvent;
   window.UIEvent =        DOM.UIEvent;
-  window.screen =         new Screen();
+  const screen =         new Screen();
+  Object.defineProperty(window, 'screen',{
+    get(){
+      return screen;
+    }
+  });
 
   // for inline event handlers
   window._globalProxy.Function = Function;
diff --git a/src/dom/scripts.js b/src/dom/scripts.js
index 956574b1a..a2b2b3fcd 100644
--- a/src/dom/scripts.js
+++ b/src/dom/scripts.js
@@ -43,11 +43,18 @@ Object.defineProperty(HTMLScriptElementImpl, 'init', {
       }
 
     }
+    obj._poppedOffStackOfOpenElements = function(){
+      //not being used, causing double js execution
+    }
   }
 });
 
 
 function _eval(text, filename) {
+  if (this._alreadyStarted) 
+    return;
+  
+  this._alreadyStarted = true;
   const typeString = this._getTypeString();
   const _defaultView = this._ownerDocument._defaultView;
   if (_defaultView && _defaultView._runScripts === 'dangerously' && jsMIMETypes.has(typeString.toLowerCase())) {
diff --git a/src/xhr.js b/src/xhr.js
index 1b21f920c..41062d5c3 100644
--- a/src/xhr.js
+++ b/src/xhr.js
@@ -179,14 +179,12 @@ class XMLHttpRequest {
       // CORS request, check origin, may lead to new error
       if (this._cors) {
         const allowedOrigin = response.headers.get('Access-Control-Allow-Origin');
-        if (!(allowedOrigin === '*' || allowedOrigin === this._cors)) {
-          this._error = new DOMException(DOMException.SECURITY_ERR, 'Cannot make request to different domain');          
-        }
+        if (!(allowedOrigin === '*' || allowedOrigin === this._cors)) 
+          this._error = new DOMException(DOMException.SECURITY_ERR, 'Cannot make request to different domain')          
         else if (!/^(GET|HEAD|POST)$/.test(this._method)) {
           const allowedMethods = response.headers.get('Access-Control-Allow-Methods');        
-          if (!allowedMethods || allowedMethods.indexOf(request.method) == -1) {
+          if (!allowedMethods || allowedMethods.indexOf(request.method) == -1) 
             this._error = new DOMException(DOMException.SECURITY_ERR, 'Cannot make request with not-allowed method('+this._method+')');            
-          }
         }   
         if (this._error) {
           this._browser.errors.push(this._error);