How can I add property of a Model in its JSON made using `django.core.serializers` to return in `AJAX` call?

I have a Model:

```
class MyModel(models.Model):
...
@property
def a_property(self):
    return some_value;

```

Then in views, I send a JSON of this model in an AJAX call. The problem is, I don't know how to send value returned by this property. I tried

```
query_set = MyModel.objects.flter(...)
serializers.serialize('json', query_set, fields=('...', ... , 'a_property'))

```

But this doesn't work. How can I pass the value of this property?