diff --git a/lib/request.js b/lib/request.js
index 19ecca3..be90cf8 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -27,7 +27,7 @@ var Request = module.exports = function (xhr, params) {
         });
     }
     
-    var res = new Response;
+    var res = new Response(xhr);
     res.on('ready', function () {
         self.emit('response', res);
     });
diff --git a/lib/response.js b/lib/response.js
index ae2844b..e168787 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -1,6 +1,7 @@
 var EventEmitter = require('events').EventEmitter;
 
-var Response = module.exports = function (res) {
+var Response = module.exports = function (xhr) {
+    this.xhr = xhr;
     this.offset = 0;
 };
 
@@ -11,8 +12,8 @@ var capable = {
     status2 : true
 };
 
-function parseHeaders (res) {
-    var lines = res.getAllResponseHeaders().split(/\r?\n/);
+function parseHeaders (xhr) {
+    var lines = xhr.getAllResponseHeaders().split(/\r?\n/);
     var headers = {};
     for (var i = 0; i < lines.length; i++) {
         var line = lines[i];
@@ -43,14 +44,20 @@ function parseHeaders (res) {
 }
 
 Response.prototype.getHeader = function (key) {
-    return this.headers[key.toLowerCase()];
+    var header = this.headers[key.toLowerCase()];
+
+    // Work around Mozilla bug #608735 [https://bugzil.la/608735], which causes
+    // getAllResponseHeaders() to return {} if the response is a CORS request.
+    // xhr.getHeader still works correctly.
+    return header || this.xhr.getResponseHeader(key);
 };
 
-Response.prototype.handle = function (res) {
-    if (res.readyState === 2 && capable.status2) {
+Response.prototype.handle = function () {
+    var xhr = this.xhr;
+    if (xhr.readyState === 2 && capable.status2) {
         try {
-            this.statusCode = res.status;
-            this.headers = parseHeaders(res);
+            this.statusCode = xhr.status;
+            this.headers = parseHeaders(xhr);
         }
         catch (err) {
             capable.status2 = false;
@@ -60,40 +67,41 @@ Response.prototype.handle = function (res) {
             this.emit('ready');
         }
     }
-    else if (capable.streaming && res.readyState === 3) {
+    else if (capable.streaming && xhr.readyState === 3) {
         try {
             if (!this.statusCode) {
-                this.statusCode = res.status;
-                this.headers = parseHeaders(res);
+                this.statusCode = xhr.status;
+                this.headers = parseHeaders(xhr);
                 this.emit('ready');
             }
         }
         catch (err) {}
         
         try {
-            this.write(res);
+            this.write();
         }
         catch (err) {
             capable.streaming = false;
         }
     }
-    else if (res.readyState === 4) {
+    else if (xhr.readyState === 4) {
         if (!this.statusCode) {
-            this.statusCode = res.status;
+            this.statusCode = xhr.status;
             this.emit('ready');
         }
-        this.write(res);
+        this.write();
         
-        if (res.error) {
-            this.emit('error', res.responseText);
+        if (xhr.error) {
+            this.emit('error', xhr.responseText);
         }
         else this.emit('end');
     }
 };
 
-Response.prototype.write = function (res) {
-    if (res.responseText.length > this.offset) {
-        this.emit('data', res.responseText.slice(this.offset));
-        this.offset = res.responseText.length;
+Response.prototype.write = function () {
+    var xhr = this.xhr;
+    if (xhr.responseText.length > this.offset) {
+        this.emit('data', xhr.responseText.slice(this.offset));
+        this.offset = xhr.responseText.length;
     }
 };