diff --git a/src/BackgroundTokenizer.js b/src/BackgroundTokenizer.js
index f5bbe4e7..35e6f6b8 100644
--- a/src/BackgroundTokenizer.js
+++ b/src/BackgroundTokenizer.js
@@ -44,7 +44,7 @@ ace.BackgroundTokenizer = function(tokenizer) {
 
 (function(){
 
-    ace.mixin(this, ace.MEventEmitter);
+    ace.implement(this, ace.MEventEmitter);
 
     this.setTokenizer = function(tokenizer) {
         this.tokenizer = tokenizer;
diff --git a/src/Document.js b/src/Document.js
index 9f39baef..4cd8e94e 100644
--- a/src/Document.js
+++ b/src/Document.js
@@ -15,7 +15,7 @@ ace.Document = function(text, mode) {
 
 (function() {
 
-    ace.mixin(ace.Document.prototype, ace.MEventEmitter);
+    ace.implement(this, ace.MEventEmitter);
 
     this._split = function(text) {
         return text.split(/\r\n|\r|\n/);
diff --git a/src/MEventEmitter.js b/src/MEventEmitter.js
index c5951f24..80792c1d 100644
--- a/src/MEventEmitter.js
+++ b/src/MEventEmitter.js
@@ -1,38 +1,41 @@
 ace.provide("ace.MEventEmitter");
 
-ace.MEventEmitter.$initEvents = function() {
-    this._eventRegistry = {};
-};
-
-ace.MEventEmitter.$dispatchEvent = function(eventName, e) {
-    var listeners = this._eventRegistry[eventName];
-    if (!listeners || !listeners.length) return;
-
-    var e = e || {};
-    e.type = eventName;
-
-    for (var i=0; i<listeners.length; i++) {
-        listeners[i](e);
-    }
-};
-
-ace.MEventEmitter.addEventListener = function(eventName, callback) {
-    var listeners = this._eventRegistry[eventName];
-    if (!listeners) {
-      var listeners = this._eventRegistry[eventName] = [];
-    }
-    if (ace.arrayIndexOf(listeners, callback) == -1) {
-        listeners.push(callback);
-    }
-};
-
-ace.MEventEmitter.removeEventListener = function(eventName, callback) {
-    var listeners = this._eventRegistry[eventName];
-    if (!listeners) {
-      return;
-    }
-    var index = ace.arrayIndexOf(listeners, callback);
-    if (index !== -1) {
-        listeners.splice(index, 1);
-    }
+ace.MEventEmitter = function() {
+
+    this.$initEvents = function() {
+        this._eventRegistry = {};
+    };
+
+    this.$dispatchEvent = function(eventName, e) {
+        var listeners = this._eventRegistry[eventName];
+        if (!listeners || !listeners.length) return;
+
+        var e = e || {};
+        e.type = eventName;
+
+        for (var i=0; i<listeners.length; i++) {
+            listeners[i](e);
+        }
+    };
+
+    this.addEventListener = function(eventName, callback) {
+        var listeners = this._eventRegistry[eventName];
+        if (!listeners) {
+          var listeners = this._eventRegistry[eventName] = [];
+        }
+        if (ace.arrayIndexOf(listeners, callback) == -1) {
+            listeners.push(callback);
+        }
+    };
+
+    this.removeEventListener = function(eventName, callback) {
+        var listeners = this._eventRegistry[eventName];
+        if (!listeners) {
+          return;
+        }
+        var index = ace.arrayIndexOf(listeners, callback);
+        if (index !== -1) {
+            listeners.splice(index, 1);
+        }
+    };
 };
diff --git a/src/ScrollBar.js b/src/ScrollBar.js
index 4bdcb366..ad622098 100644
--- a/src/ScrollBar.js
+++ b/src/ScrollBar.js
@@ -19,7 +19,7 @@ ace.ScrollBar = function(parent) {
 
 (function() {
 
-    ace.mixin(ace.ScrollBar.prototype, ace.MEventEmitter);
+    ace.implement(this, ace.MEventEmitter);
 
     this.onScroll = function() {
       this.$dispatchEvent("scroll", {data: this.element.scrollTop});
diff --git a/src/Selection.js b/src/Selection.js
index 20598e64..d92984cf 100644
--- a/src/Selection.js
+++ b/src/Selection.js
@@ -14,7 +14,7 @@ ace.Selection = function(doc) {
 
 (function() {
 
-    ace.mixin(ace.Selection.prototype, ace.MEventEmitter);
+    ace.implement(this, ace.MEventEmitter);
 
     this.updateCursor = function() {
         this.$dispatchEvent("changeCursor", { data: this.getCursor() });
diff --git a/src/ace.js b/src/ace.js
index b4c6eee0..b84e5395 100644
--- a/src/ace.js
+++ b/src/ace.js
@@ -21,10 +21,8 @@ ace.inherits = function(ctor, superCtor) {
     ctor.prototype.constructor = ctor;
 };
 
-ace.mixin = function(obj, mixin) {
-    for (var key in mixin) {
-        obj[key] = mixin[key];
-    }
+ace.implement = function(proto, mixin) {
+    mixin.call(proto);
 };
 
 ace.addListener = function(elem, type, callback) {
@@ -81,7 +79,7 @@ ace.preventDefault = function(e) {
 
 ace.hasCssClass = function(el, name) {
     var classes = el.className.split(/\s*/g);
-    return ace.arrayIndexOf(classes, name) !== -1; 
+    return ace.arrayIndexOf(classes, name) !== -1;
 };
 
 
diff --git a/test/EventEmitterTest.js b/test/EventEmitterTest.js
index 9c7d988b..fba1793e 100644
--- a/test/EventEmitterTest.js
+++ b/test/EventEmitterTest.js
@@ -1,7 +1,7 @@
 var EventEmitter = function() {
     this.$initEvents();
 };
-ace.mixin(EventEmitter.prototype, ace.MEventEmitter);
+ace.implement(EventEmitter.prototype, ace.MEventEmitter);
 
 var EventEmitterTest = new TestCase("EventEmitterTest", {
     "test: dispatch event with no data" : function() {