Alter column with added default results in invalid PSQL query about peewee_migrate HOT 3 OPEN

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/peewee_migrate/router.py", line 152, in run_one
    migrator.run()
  File "/usr/local/lib/python3.6/site-packages/peewee_migrate/migrator.py", line 129, in run
    op.run()
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 160, in run
    self._handle_result(method(*self.args, **kwargs))
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 154, in _handle_result
    self._handle_result(item)
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 149, in _handle_result
    self.execute(result)
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 145, in execute
    self.migrator.database.execute(node)
  File "/usr/local/lib/python3.6/site-packages/playhouse/postgres_ext.py", line 464, in execute
    cursor = self.execute_sql(sql, params, commit=commit)
  File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2876, in execute_sql
    cursor.execute(sql, params or ())
psycopg2.errors.SyntaxError: syntax error at or near "VARCHAR"
LINE 1: ALTER TABLE "pgtest2" ALTER COLUMN "name" VARCHAR(123) TYPE ...
                                                  ^

Traceback (most recent call last):
  File "/usr/local/bin/pw_migrate", line 11, in <module>
    sys.exit(cli())
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/peewee_migrate/cli.py", line 63, in migrate
    migrations = router.run(name, fake=fake)
  File "/usr/local/lib/python3.6/site-packages/peewee_migrate/router.py", line 180, in run
    self.run_one(mname, migrator, fake=fake, force=fake)
  File "/usr/local/lib/python3.6/site-packages/peewee_migrate/router.py", line 152, in run_one
    migrator.run()
  File "/usr/local/lib/python3.6/site-packages/peewee_migrate/migrator.py", line 129, in run
    op.run()
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 160, in run
    self._handle_result(method(*self.args, **kwargs))
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 154, in _handle_result
    self._handle_result(item)
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 149, in _handle_result
    self.execute(result)
  File "/usr/local/lib/python3.6/site-packages/playhouse/migrate.py", line 145, in execute
    self.migrator.database.execute(node)
  File "/usr/local/lib/python3.6/site-packages/playhouse/postgres_ext.py", line 464, in execute
    cursor = self.execute_sql(sql, params, commit=commit)
  File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2876, in execute_sql
    cursor.execute(sql, params or ())
psycopg2.errors.SyntaxError: syntax error at or near "VARCHAR"
LINE 1: ALTER TABLE "pgtest2" ALTER COLUMN "name" VARCHAR(123) TYPE ...
                                                  ^