How do I make Mypy recognize non-nullable ORM attributes?

Mypy infers ORM non-nullable instance attributes as optionals.

Filename: test.py

from sqlalchemy.orm import decl_api, registry
from sqlalchemy import BigInteger, Column, String

mapper_registry = registry()


class Base(metaclass=decl_api.DeclarativeMeta):
    __abstract__ = True

    registry = mapper_registry
    metadata = mapper_registry.metadata

    __init__ = mapper_registry.constructor


class Person(Base):
    __tablename__ = "persons"

    id = Column(BigInteger, primary_key=True, autoincrement=True)
    name = Column(String(40), nullable=False)


def main(person: Person):
    person_id = person.id
    person_name = person.name

    reveal_locals()

Running mypy test.py yields:

test.py:27: note: Revealed local types are:
test.py:27: note:     person: test.Person
test.py:27: note:     person_id: Union[builtins.int, None]
test.py:27: note:     person_name: Union[builtins.str, None]

As far as my understanding goes, person_id and person_name should have been int and str respectively since they are set as non-nullable.

What am I missing here?

Relevant libraries:

SQLAlchemy         1.4.25
sqlalchemy2-stubs  0.0.2a15
mypy               0.910
mypy-extensions    0.4.3