diff --git a/index.js b/index.js
index fd18c96..0da411d 100644
--- a/index.js
+++ b/index.js
@@ -1,5 +1,5 @@
 (function() {
   'use strict';
 
-  module.exports = require('./lib/xmlhttprequest');
+  module.exports = require('./lib');
 })();
diff --git a/lib/anonxmlhttprequest.js b/lib/anonxmlhttprequest.js
new file mode 100644
index 0000000..7bc3d80
--- /dev/null
+++ b/lib/anonxmlhttprequest.js
@@ -0,0 +1,14 @@
+(function() {
+  'use strict';
+
+  var XMLHttpRequest = require('./xmlhttprequest');
+
+  function AnonXMLHttpRequest() {
+    if (!(this instanceof AnonXMLHttpRequest)) {
+      throw new TypeError('DOM object constructor cannot be called as a function');
+    }
+    XMLHttpRequest.call(this);
+  }
+  AnonXMLHttpRequest.prototype = Object.create(XMLHttpRequest.prototype);
+  module.exports = AnonXMLHttpRequest;
+})();
diff --git a/lib/eventtarget.js b/lib/eventtarget.js
new file mode 100644
index 0000000..16a711b
--- /dev/null
+++ b/lib/eventtarget.js
@@ -0,0 +1,30 @@
+(function() {
+  'use strict';
+
+  function EventTarget() {
+    Object.defineProperty(this, '_eventListeners', {
+      value: {},
+      writable: true,
+      enumerable: false,
+      configurable: false
+    });
+  }
+  module.exports = EventTarget;
+
+  (function(proto) {
+    proto.addEventListener = function addEventListener(type, listener, useCapture) {
+      this['on' + type] = listener;
+    };
+
+    proto.dispatchEvent = function dispatchEvent(event) {
+      var _listener = this['on' + event.type];
+      if (typeof(_listener) === 'function') {
+        _listener.call(this, event);
+      }
+    };
+
+    proto.removeEventListener = function removeEventListener(type, listener, useCapture) {
+      // todo
+    };
+  })(EventTarget.prototype);
+})();
diff --git a/lib/formdata.js b/lib/formdata.js
new file mode 100644
index 0000000..de77305
--- /dev/null
+++ b/lib/formdata.js
@@ -0,0 +1,16 @@
+(function() {
+  'use strict';
+
+  function FormData() {
+    if (!(this instanceof FormData)) {
+      throw new TypeError('DOM object constructor cannot be called as a function.');
+    }
+  }
+  module.exports = FormData;
+
+  (function(proto) {
+    proto.append = function append(name, value, filename) {
+      // todo
+    };
+  })(FormData.prototype);
+})();
diff --git a/lib/index.js b/lib/index.js
new file mode 100644
index 0000000..dd7f76f
--- /dev/null
+++ b/lib/index.js
@@ -0,0 +1,15 @@
+(function() {
+  'use strict';
+
+  var XMLHttpRequestUpload = require('./xmlhttprequestupload');
+  var XMLHttpRequest = require('./xmlhttprequest');
+  var AnonXMLHttpRequest = require('./anonxmlhttprequest');
+  var FormData = require('./formdata');
+
+  module.exports = {
+    XMLHttpRequestUpload: XMLHttpRequestUpload,
+    XMLHttpRequest: XMLHttpRequest,
+    AnonXMLHttpRequest: AnonXMLHttpRequest,
+    FormData: FormData
+  };
+})();
diff --git a/lib/xmlhttprequest.js b/lib/xmlhttprequest.js
index e067005..a1be843 100644
--- a/lib/xmlhttprequest.js
+++ b/lib/xmlhttprequest.js
@@ -4,88 +4,9 @@
   var http = require('http');
   var https = require('https');
   var urlparse = require('url').parse;
-
-  function EventTarget() {
-    Object.defineProperty(this, '_eventListeners', {
-      value: {},
-      writable: true,
-      enumerable: false,
-      configurable: false
-    });
-  }
-
-  (function(proto) {
-    proto.addEventListener = function addEventListener(type, listener, useCapture) {
-      this['on' + type] = listener;
-    };
-
-    proto.dispatchEvent = function dispatchEvent(event) {
-      var _listener = this['on' + event.type];
-      if (typeof(_listener) === 'function') {
-        _listener.call(this, event);
-      }
-    };
-
-    proto.removeEventListener = function removeEventListener(type, listener, useCapture) {
-      // todo
-    };
-  })(EventTarget.prototype);
-
-  function XMLHttpRequestEventTarget() {
-    EventTarget.call(this);
-  }
-  XMLHttpRequestEventTarget.prototype = Object.create(EventTarget.prototype);
-
-  (function(proto) {
-    // Event handler
-    (function(types) {
-      types.forEach(function(type) {
-        Object.defineProperty(proto, 'on' + type, {
-          get: function() {
-            var _listener = this._eventListeners[type];
-            if (typeof(_listener) !== 'function') {
-              return null;
-            }
-            return _listener;
-          },
-          set: function(listener) {
-            if (typeof(listener) !== 'function') {
-              delete this._eventListeners[type];
-              return listener;
-            }
-            return this._eventListeners[type] = listener;
-          },
-          enumerable: true,
-          configurable: false
-        });
-      });
-    })([
-      'loadstart',
-      'progress',
-      'abort',
-      'error', // todo
-      'load',
-      'timeout', // todo
-      'loadend'
-    ]);
-  })(XMLHttpRequestEventTarget.prototype);
-
-  function XMLHttpRequestUpload() {
-    if (!(this instanceof XMLHttpRequestUpload)) {
-      throw new TypeError('DOM object constructor cannot be called as a function.');
-    }
-    XMLHttpRequestEventTarget.call(this);
-  }
-  XMLHttpRequestUpload.prototype = Object.create(XMLHttpRequestEventTarget.prototype);
-
-  var XMLHttpRequestResponseType = [
-    '',
-    'arraybuffer',
-    'blob',
-    'document',
-    'json',
-    'text'
-  ];
+  var XMLHttpRequestEventTarget = require('./xmlhttprequesteventtarget');
+  var XMLHttpRequestUpload = require('./xmlhttprequestupload');
+  var XMLHttpRequestResponseType = require('./xmlhttprequestresponsetype');
 
   function XMLHttpRequest() {
     if (!(this instanceof XMLHttpRequest)) {
@@ -128,6 +49,7 @@
     this.statusText = '';
   }
   XMLHttpRequest.prototype = Object.create(XMLHttpRequestEventTarget.prototype);
+  module.exports = XMLHttpRequest;
 
   (function(proto) {
     // Event handler
@@ -366,30 +288,4 @@
       }.bind(this));
     };
   })(XMLHttpRequest.prototype);
-
-  function AnonXMLHttpRequest() {
-    if (!(this instanceof AnonXMLHttpRequest)) {
-      throw new TypeError('DOM object constructor cannot be called as a function');
-    }
-    XMLHttpRequest.call(this);
-  }
-  AnonXMLHttpRequest.prototype = Object.create(XMLHttpRequest.prototype);
-
-  function FormData() {
-    if (!(this instanceof FormData)) {
-      throw new TypeError('DOM object constructor cannot be called as a function.');
-    }
-  }
-
-  (function(proto) {
-    proto.append = function append(name, value, filename) {
-      // todo
-    };
-  })(FormData.prototype);
-
-  XMLHttpRequest.XMLHttpRequestUpload = XMLHttpRequestUpload;
-  XMLHttpRequest.XMLHttpRequest = XMLHttpRequest;
-  XMLHttpRequest.AnonXMLHttpRequest = AnonXMLHttpRequest;
-  XMLHttpRequest.FormData = FormData;
-  module.exports = XMLHttpRequest;
 })();
diff --git a/lib/xmlhttprequesteventtarget.js b/lib/xmlhttprequesteventtarget.js
new file mode 100644
index 0000000..a9fa39c
--- /dev/null
+++ b/lib/xmlhttprequesteventtarget.js
@@ -0,0 +1,45 @@
+(function() {
+  'use strict';
+
+  var EventTarget = require('./eventtarget');
+
+  function XMLHttpRequestEventTarget() {
+    EventTarget.call(this);
+  }
+  XMLHttpRequestEventTarget.prototype = Object.create(EventTarget.prototype);
+  module.exports = XMLHttpRequestEventTarget;
+
+  (function(proto) {
+    // Event handler
+    (function(types) {
+      types.forEach(function(type) {
+        Object.defineProperty(proto, 'on' + type, {
+          get: function() {
+            var _listener = this._eventListeners[type];
+            if (typeof(_listener) !== 'function') {
+              return null;
+            }
+            return _listener;
+          },
+          set: function(listener) {
+            if (typeof(listener) !== 'function') {
+              delete this._eventListeners[type];
+              return listener;
+            }
+            return this._eventListeners[type] = listener;
+          },
+          enumerable: true,
+          configurable: false
+        });
+      });
+    })([
+      'loadstart',
+      'progress',
+      'abort',
+      'error', // todo
+      'load',
+      'timeout', // todo
+      'loadend'
+    ]);
+  })(XMLHttpRequestEventTarget.prototype);
+})();
diff --git a/lib/xmlhttprequestresponsetype.js b/lib/xmlhttprequestresponsetype.js
new file mode 100644
index 0000000..2892c9c
--- /dev/null
+++ b/lib/xmlhttprequestresponsetype.js
@@ -0,0 +1,13 @@
+(function() {
+  'use strict';
+
+  var XMLHttpRequestResponseType = [
+    '',
+    'arraybuffer',
+    'blob',
+    'document',
+    'json',
+    'text'
+  ];
+  module.exports = XMLHttpRequestResponseType;
+})();
diff --git a/lib/xmlhttprequestupload.js b/lib/xmlhttprequestupload.js
new file mode 100644
index 0000000..2aac008
--- /dev/null
+++ b/lib/xmlhttprequestupload.js
@@ -0,0 +1,14 @@
+(function() {
+  'use strict';
+
+  var XMLHttpRequestEventTarget = require('./xmlhttprequesteventtarget');
+
+  function XMLHttpRequestUpload() {
+    if (!(this instanceof XMLHttpRequestUpload)) {
+      throw new TypeError('DOM object constructor cannot be called as a function.');
+    }
+    XMLHttpRequestEventTarget.call(this);
+  }
+  XMLHttpRequestUpload.prototype = Object.create(XMLHttpRequestEventTarget.prototype);
+  module.exports = XMLHttpRequestUpload;
+})();