South Doesn't Seem to Like PostgreSQLUUIDField

Question

I'm having an issue using django_extensions.db.fields.PostgreSQLUUIDField with my Django models because South will keep trying to force the field to become a CharField every time schemamigration is run.

As a result I seem to be forced to hand-edit the migrations to remove:

db.alter_column('testapp_testmodel', 'guid', self.gf('django.db.models.fields.CharField')(max_length=64, primary_key=True))

and edit the frozen model definitions below from:

'guid': ('django.db.models.fields.CharField', [], {'max_length': '64', 'primary_key': 'True'}),

to:

'guid': ('django_extensions.db.fields.PostgreSQLUUIDField', [], {'max_length': '64', 'primary_key': 'True'}),

Am I missing something obvious here?