diff --git a/lib/XMLHttpRequest.js b/lib/XMLHttpRequest.js
index 3223020..50f6158 100644
--- a/lib/XMLHttpRequest.js
+++ b/lib/XMLHttpRequest.js
@@ -102,6 +102,7 @@ function XMLHttpRequest(opts) {
   var sendFlag = false;
   // Error flag, used when errors occur or abort is called
   var errorFlag = false;
+  var abortedFlag = false;
 
   // Event listeners
   var listeners = {};
@@ -172,10 +173,11 @@ function XMLHttpRequest(opts) {
   this.open = function(method, url, async, user, password) {
     this.abort();
     errorFlag = false;
+    abortedFlag = false;
 
     // Check for valid request method
     if (!isAllowedHttpMethod(method)) {
-      throw "SecurityError: Request method not allowed";
+      throw new Error("SecurityError: Request method not allowed");
     }
 
     settings = {
@@ -208,16 +210,14 @@ function XMLHttpRequest(opts) {
    */
   this.setRequestHeader = function(header, value) {
     if (this.readyState != this.OPENED) {
-      throw "INVALID_STATE_ERR: setRequestHeader can only be called when state is OPEN";
-      return false;
+      throw new Error("INVALID_STATE_ERR: setRequestHeader can only be called when state is OPEN");
     }
     if (!isAllowedHttpHeader(header)) {
       console.warn('Refused to set unsafe header "' + header + '"');
       return false;
     }
     if (sendFlag) {
-      throw "INVALID_STATE_ERR: send flag is true";
-      return false;
+      throw new Error("INVALID_STATE_ERR: send flag is true");
     }
     headers[header] = value;
     return true;
@@ -283,11 +283,11 @@ function XMLHttpRequest(opts) {
    */
   this.send = function(data) {
     if (this.readyState != this.OPENED) {
-      throw "INVALID_STATE_ERR: connection must be opened before send() is called";
+      throw new Error("INVALID_STATE_ERR: connection must be opened before send() is called");
     }
 
     if (sendFlag) {
-      throw "INVALID_STATE_ERR: send has already been called";
+      throw new Error("INVALID_STATE_ERR: send has already been called");
     }
 
     var ssl = false, local = false;
@@ -312,13 +312,13 @@ function XMLHttpRequest(opts) {
         break;
 
       default:
-        throw "Protocol not supported.";
+        throw new Error("Protocol not supported.");
     }
 
     // Load files off the local filesystem (file://)
     if (local) {
       if (settings.method !== "GET") {
-        throw "XMLHttpRequest: Only GET method is supported";
+        throw new Error("XMLHttpRequest: Only GET method is supported");
       }
 
       if (settings.async) {
@@ -402,7 +402,6 @@ function XMLHttpRequest(opts) {
 
     // Reset error flag
     errorFlag = false;
-
     // Handle async requests
     if (settings.async) {
       // Use the proper protocol
@@ -545,7 +544,7 @@ function XMLHttpRequest(opts) {
       if (self.responseText.match(/^NODE-XMLHTTPREQUEST-ERROR:/)) {
         // If the file returned an error, handle it
         var errorObj = self.responseText.replace(/^NODE-XMLHTTPREQUEST-ERROR:/, "");
-        self.handleError(errorObj);
+        self.handleError(errorObj, 503);
       } else {
         // If the file returned okay, parse its data and move to the DONE state
         self.status = self.responseText.replace(/^NODE-XMLHTTPREQUEST-STATUS:([0-9]*),.*/, "$1");
@@ -557,9 +556,10 @@ function XMLHttpRequest(opts) {
 
   /**
    * Called when an error is encountered to deal with it.
+   * @param  status  {number}    HTTP status code to use rather than the default (0) for XHR errors.
    */
-  this.handleError = function(error) {
-    this.status = 503;
+  this.handleError = function(error, status) {
+    this.status = +status || 0;
     this.statusText = error;
     this.responseText = error.stack;
     errorFlag = true;
@@ -579,8 +579,7 @@ function XMLHttpRequest(opts) {
     this.responseText = "";
     this.responseXML = "";
 
-    errorFlag = true;
-
+    errorFlag = abortedFlag = true
     if (this.readyState !== this.UNSENT
         && (this.readyState !== this.OPENED || sendFlag)
         && this.readyState !== this.DONE) {
@@ -619,11 +618,17 @@ function XMLHttpRequest(opts) {
    */
   this.dispatchEvent = function(event) {
     if (typeof self["on" + event] === "function") {
-      self["on" + event]();
+      if (this.readyState === this.DONE)
+        setImmediate(function() { self["on" + event]() })
+      else
+        self["on" + event]()
     }
     if (event in listeners) {
-      for (var i = 0, len = listeners[event].length; i < len; i++) {
-        listeners[event][i].call(self);
+      for (let i = 0, len = listeners[event].length; i < len; i++) {
+        if (this.readyState === this.DONE)
+          setImmediate(function() { listeners[event][i].call(self) })
+        else
+          listeners[event][i].call(self)
       }
     }
   };
@@ -634,18 +639,29 @@ function XMLHttpRequest(opts) {
    * @param int state New state
    */
   var setState = function(state) {
-    if (self.readyState !== state) {
-      self.readyState = state;
+    if ((self.readyState === state) || (self.readyState === self.UNSENT && abortedFlag))
+      return
 
-      if (settings.async || self.readyState < self.OPENED || self.readyState === self.DONE) {
-        self.dispatchEvent("readystatechange");
-      }
+    self.readyState = state;
 
-      if (self.readyState === self.DONE && !errorFlag) {
-        self.dispatchEvent("load");
-        // @TODO figure out InspectorInstrumentation::didLoadXHR(cookie)
-        self.dispatchEvent("loadend");
-      }
+    if (settings.async || self.readyState < self.OPENED || self.readyState === self.DONE) {
+      self.dispatchEvent("readystatechange");
+    }
+
+    if (self.readyState === self.DONE) {
+      let fire
+
+      if (abortedFlag)
+        fire = "abort"
+      else if (errorFlag)
+        fire = "error"
+      else
+        fire = "load"
+
+      self.dispatchEvent(fire)
+
+      // @TODO figure out InspectorInstrumentation::didLoadXHR(cookie)
+      self.dispatchEvent("loadend");
     }
   };
 };
diff --git a/package.json b/package.json
index 1738267..55ab8fd 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "xmlhttprequest-ssl",
   "description": "XMLHttpRequest for Node",
-  "version": "1.5.5",
+  "version": "1.5.6",
   "author": {
     "name": "Michael de Wit"
   },