Djangoの管理画面の入力(input)にクラスを追加する方法

admin.py

class HogeAdmin(admin.ModelAdmin):

    def formfield_for_dbfield(self, db_field, **kwargs):
        formfield = super().formfield_for_dbfield(db_field, **kwargs)
        formfield.widget.attrs.update({'class': 'form-control'})
        return formfield