I'm using mongodb as database and trying to extend the django's inbuilt user model.
here's the error I'm getting:

```
django.core.exceptions.ValidationError: ['Field "auth.User.id" of model container:"<class \'django.contrib.auth.models.User\'>" cannot be of type "<class \'django.db.models.fields.AutoField\'>"']

```

Here's my `models.py`:

```
from djongo import models
from django.contrib.auth.models import User

class Profile(models.Model):
    user = models.EmbeddedField(model_container=User)
    mobile = models.PositiveIntegerField()
    address = models.CharField(max_length=200)
    pincode = models.PositiveIntegerField()

```