Using ULID field for primary key causing migration to keep being recreated

[opentyler]

I'm using ULID as the primary key for a couple of my models, as well as ULID for a couple non-PK keys. When i run python manage.py makemigrations, a migration is made attempting to redeclare the ulid fields being used as pk, but the non-pk fields aren't affected which is good. If I try to run the migration, it results with an error, reproduced below.

Not sure why django wants to keep creating this migration, as its the exact same operation as the initial migration.

models.py:

class Document(MP_Node):
    id = ULIDField(default=default, primary_key=True, editable=False)
    tree_root_pk = ULIDField(null=True, blank=True)

class Tag(models.Model):
    id = ULIDField(default=default, primary_key=True, editable=False)

Initial migration:

migrations.CreateModel(
    name='Tag',
    fields=[
        ('id', django_ulid.models.ULIDField(default=ulid.api.api.Api.new, editable=False, primary_key=True, serialize=False)),

migrations.CreateModel(
    name='Document',
    fields=[
        ('id', django_ulid.models.ULIDField(default=ulid.api.api.Api.new, editable=False, primary_key=True, serialize=False)),
        ('tree_root_pk', django_ulid.models.ULIDField(blank=True, null=True)),

Migration that keeps getting recreated every time I run python manage.py makemigrations:

operations = [
    migrations.AlterField(
        model_name='document',
        name='id',
        field=django_ulid.models.ULIDField(default=ulid.api.api.Api.new, editable=False, primary_key=True, serialize=False),
    ),
    migrations.AlterField(
        model_name='tag',
        name='id',
        field=django_ulid.models.ULIDField(default=ulid.api.api.Api.new, editable=False, primary_key=True, serialize=False),
    ),
]

The error I get if I try to run this superfluous migration:

Operations to perform:
  Apply all migrations: admin, auth, contenttypes, djstripe, documents, sessions, users
Running migrations:
  Applying documents.0003_auto_20201022_1945...Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "lib/python3.7/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "lib/python3.7/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "lib/python3.7/site-packages/django/core/management/base.py", line 328, in run_from_argv
    self.execute(*args, **cmd_options)
  File "lib/python3.7/site-packages/django/core/management/base.py", line 369, in execute
    output = self.handle(*args, **options)
  File "lib/python3.7/site-packages/django/core/management/base.py", line 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 233, in handle
    fake_initial=fake_initial,
  File "lib/python3.7/site-packages/django/db/migrations/executor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "lib/python3.7/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "lib/python3.7/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
    state = migration.apply(state, schema_editor)
  File "lib/python3.7/site-packages/django/db/migrations/migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "lib/python3.7/site-packages/django/db/migrations/operations/fields.py", line 249, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "lib/python3.7/site-packages/django/db/backends/base/schema.py", line 565, in alter_field
    old_db_params, new_db_params, strict)
  File "lib/python3.7/site-packages/django/db/backends/postgresql/schema.py", line 154, in _alter_field
    new_db_params, strict,
  File "lib/python3.7/site-packages/django/db/backends/base/schema.py", line 678, in _alter_field
    old_default = self.effective_default(old_field)
  File "lib/python3.7/site-packages/django/db/backends/base/schema.py", line 303, in effective_default
    return field.get_db_prep_save(self._effective_default(field), self.connection)
  File "lib/python3.7/site-packages/django/db/backends/base/schema.py", line 282, in _effective_default
    default = field.get_default()
  File "lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 829, in get_default
    return self._get_default()
TypeError: new() missing 1 required positional argument: 'self'