Computed property not working on IE8?

I have the following simple test script:

Common.TestModel = Ember.Object.exted({
   displayName: Ember.computed(function() {
      return this.get('name') + ' display';

var data = Ember.Object.create({name: 'name'});
var obj = Common.TestModel.create(data);
console.log(obj.get('displayName')); // This outputs "undefined" on IE8

It seems computed properties work properly on templates. Is there anything obvious I do not know here? Thanks a lot!

I figured out the reason. It is caused by some difference in get property behavior on IE8.