Django custom selectfield with initial

I have a selectfield which I override a charfield in my model. I can't use a foreignkey at all on the field.

class AliasForm(forms.ModelForm):
    account = forms.ModelChoiceField(queryset=Account.objects.all(), widget=forms.HiddenInput())
    domain = forms.ModelChoiceField(queryset=Domain.obje开发者_Go百科cts.all(), widget=forms.HiddenInput())
    end = forms.ModelChoiceField(queryset=Mailbox.objects.all())

    def __init__(self, *args, **kwargs):
        self.account = kwargs.pop('account', None)
        super(AliasForm, self).__init__(*args, **kwargs)
        if self.account:
            self.fields['end'].queryset = Mailbox.objects.filter(account=self.account)

How can I make end get passed in a value where it is autoselected?

Ok figured it out.

I needed to pass in initial but with instance.id and not instance

form = AliasForm(initial={'end': mailbox.id})

I was doing just 'end': mailbox