diff --git a/CHANGELOG b/CHANGELOG
index 06ea003..67dc3c6 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,5 @@
+* Fix toString/valueOf sharing same method reference via closure in Class#addMethods. Use plain property assignment, since Object.extend fails to enumerate over toString/valueOf. (kangax)
+
 * Stop Form.Element.disable from stealing focus. (jddalton)
 
 * Ensure Element.hide and Element.show return an element, even if you pass an element ID. (Andrew Dupont)
diff --git a/src/base.js b/src/base.js
index 3074e2e..df1b97e 100644
--- a/src/base.js
+++ b/src/base.js
@@ -44,12 +44,13 @@ Class.Methods = {
       var property = properties[i], value = source[property];
       if (ancestor && Object.isFunction(value) &&
           value.argumentNames().first() == "$super") {
-        var method = value, value = Object.extend((function(m) { 
+        var method = value;
+        value = (function(m) {
           return function() { return ancestor[m].apply(this, arguments) };
-        })(property).wrap(method), {
-          valueOf:  function() { return method },
-          toString: function() { return method.toString() }  
-        });
+        })(property).wrap(method);
+
+        value.valueOf = method.valueOf.bind(method);
+        value.toString = method.toString.bind(method);
       }
       this.prototype[property] = value;
     }
diff --git a/test/unit/base_test.js b/test/unit/base_test.js
index 6624cac..9b13849 100644
--- a/test/unit/base_test.js
+++ b/test/unit/base_test.js
@@ -498,6 +498,17 @@ new Test.Unit.Runner({
       valueOf: function() { return "valueOf" }
     });
     
+    var Parent = Class.create({
+      m1: function(){ return 'm1' },
+      m2: function(){ return 'm2' }
+    });
+    var Child = Class.create(Parent, {
+      m1: function($super) { return 'm1 child' },
+      m2: function($super) { return 'm2 child' }
+    });
+    
+    this.assert(new Child().m1.toString().indexOf('m1 child') > -1);
+    
     this.assertEqual("toString", new Foo().toString());
     this.assertEqual("valueOf", new Foo().valueOf());
   }