Mypy error: "int" is not callable

[sergeyglazyrindev]

Hello guys.
I use arrow 1.2.3 and python 3.9, and I am getting mypy error for the following code:

import arrow


class DateTimeFactory(arrow.Arrow):

    def make_project_datetime(self):
        return self.datetime.replace(tzinfo=None)


datetime_factory = arrow.ArrowFactory(DateTimeFactory)

and in this line I am getting mypy error: "int" is not callable

datetime_factory.get(field_val).make_project_datetime()

where field_val has type: typing.Any
I tried to remove part make_project_datetime and mypy doesn't report any error in this line, so, it's considering that make_project_datetime attribute has type int...
Could anyone suggest what could be the problem ? And how to fix it properly ?