order_with_respect_to fails on a relationship on a model that has not yet been defined

[Goldan]

If I specify 'order_with_respect_to' on a field linked to a model that hasn't been defined yet, I get the following error:
<...>File "/usr/lib/python2.6/dist-packages/django/db/models/base.py", line 223, in _prepare

setattr(opts.order_with_respect_to.rel.to, 'get_%s_order' % cls.name.lower(), curry(method_get_order, cls))

AttributeError: 'str' object has no attribute 'get_location_order'

When I swap declarations of Location and City models, the error disappears.

Here is the code:

class Location(TimeStampedModel):

Single location on a map, e.g. building.
address = models.CharField(u"адрес", max_length=75, help_text=u"Улица, корпус, дом")
city = models.ForeignKey('City', related_name="locations", verbose_name=u"город")
metro_stations = models.ManyToManyField('MetroStation', related_name="locations", verbose_name=u"ближайшие станции метро", blank=True, null=True)

class Meta:

verbose_name = u"адрес"
verbose_name_plural = u"адреса"
order_with_respect_to = 'city'

class City(TimeStampedModel):

A city.
name = models.CharField(u"название", max_length=30)

class Meta:

verbose_name = u"город"
verbose_name_plural = u"города"