Call to a member function getDateFormat() on null, laravel/passport install

I am getting a

  [Symfony\Component\Debug\Exception\FatalThrowableError] Call to a member function getDateFormat() on null

when running "php artisan passport:install" on a laravel/mongodb api project. I have tried changing "use Illuminate\Database\Eloquent\Model;" to "use Jenssegers\Mongodb\Eloquent\Model as Model;" in my user and client.php but it still throws the exception.

any ideas??

via Chebli Mohamed