diff --git a/src/drivers/webextension/js/content.js b/src/drivers/webextension/js/content.js
index 7ad284495..df11d725b 100644
--- a/src/drivers/webextension/js/content.js
+++ b/src/drivers/webextension/js/content.js
@@ -35,7 +35,25 @@ if ( typeof browser !== 'undefined' && typeof document.body !== 'undefined' ) {
     script.setAttribute('id', 'wappalyzerEnvDetection');
     script.setAttribute('src', browser.extension.getURL('js/inject.js'));
 
-    container.addEventListener('wappalyzerEvent', (event => {
+    container.addEventListener('wappalyzerEnvEvent', (event => {
+      browser.runtime.sendMessage({
+        id: 'JS_ready',
+        subject: { },
+        source: 'content.js'
+      }, response => {
+        window.postMessage({patterns: response.patterns}, "*");
+      });
+      window.addEventListener('message', (event => {
+        if (event.data.js === undefined)
+          return;
+        var js = event.data.js ;
+        browser.runtime.sendMessage({
+          id: 'analyze',
+          subject: { js },
+          source: 'content.js'
+        });
+      }), true);
+
       var env = event.target.childNodes[0].nodeValue;
 
       document.documentElement.removeChild(container);
diff --git a/src/drivers/webextension/js/inject.js b/src/drivers/webextension/js/inject.js
index 731db3366..26ac3d6eb 100644
--- a/src/drivers/webextension/js/inject.js
+++ b/src/drivers/webextension/js/inject.js
@@ -1,42 +1,33 @@
 (function() {
 	try {
-		var i, environmentVars = '', e = document.createEvent('Events');
+		var i, environmentVars = '', eEnv = document.createEvent('Events'), container = document.getElementById('wappalyzerData');
 
-		e.initEvent('wappalyzerEvent', true, false);
+		eEnv.initEvent('wappalyzerEnvEvent', true, false);
 
 		for ( i in window ) {
 			environmentVars += i + ' ';
 		}
+		container.appendChild(document.createComment(environmentVars));
+		container.dispatchEvent(eEnv);
 
-		document.getElementById('wappalyzerData').appendChild(document.createComment(environmentVars));
-		document.getElementById('wappalyzerData').dispatchEvent(e);
-
-		// Handle property match
-		browser.runtime.sendMessage({
-			id: 'JS_ready',
-			subject: { },
-			source: 'inject.js'
-		}, response => {
-			var properties = response.patterns;
+		window.addEventListener('message', (event => {
+			if (event.data.patterns === undefined)
+				return;
+			var properties = event.data.patterns;
 			var js = {};
-			Object.keys(properties).forEach(app => {
-				Object.keys(properties[app]).forEach(property => {
+			Object.keys(properties).forEach(appname => {
+				Object.keys(properties[appname]).forEach(property => {
 					var content = false;
 					if( content = JSdetection(property) ){
-						if ( js[appname]  === undefined ) {
+						if ( js[appname]  === undefined )
 							js[appname] = {};
-						}
-						js[appname][property] = properties[app][property];
+						js[appname][property] = properties[appname][property];
 						js[appname][property]["content"] = content;
 					}
 				});
 			});
-			browser.runtime.sendMessage({
-				id: 'analyze',
-				subject: { js },
-				source: 'inject.js'
-			});
-		});
+			window.postMessage({js: js}, "*");
+		}), false);
 	} catch(e) {
 		// Fail quietly
 	}
@@ -49,4 +40,4 @@ function JSdetection(p){
 	}, window);
 
 	return typeof value === 'string' ? value : !!value;
-}
\ No newline at end of file
+}
diff --git a/src/wappalyzer.js b/src/wappalyzer.js
index d76e604f0..74fd66393 100644
--- a/src/wappalyzer.js
+++ b/src/wappalyzer.js
@@ -18,7 +18,7 @@ class Wappalyzer {
     this.apps = {};
     this.categories = {};
     this.driver = {};
-    this.parsedJS = {};
+    this.parsedJS = undefined;
 
     this.detected = {};
     this.hostnameCache = {};
@@ -85,7 +85,7 @@ class Wappalyzer {
 
     if ( data.js ) {
       Object.keys(data.js).forEach(appName => {
-        this.analyzeJS(this.apps[appname], data.js[appname])
+        this.analyzeJS(apps[appName], data.js[appName]);
       });
     }
 
@@ -255,14 +255,13 @@ class Wappalyzer {
    * Parse JS patterns
    */
   parseJS() {
-    if ( this.parsedJS == {} ){
+    if ( this.parsedJS === undefined){
+      this.parsedJS = {};
       Object.keys(this.apps).forEach(appName => {
-        if (apps[appName].props.js){
-          parsedJS[appName] = this.parsePatterns(apps[appName].props.js);
-        }
+        if (this.apps[appName].js)
+          this.parsedJS[appName] = this.parsePatterns(this.apps[appName].js);
       });
     }
-    return this.parsedJS
   }
 
   resolveExcludes(apps) {