Using attrs decorators in PyCharm

Question

I have the following attrs class:

from attrs import define, field

@define
class Foo:
    bar: int = field()
    
    @bar.validator
    def check(self, attribute, value):
        ...

It works normally at runtime, as expected:

lorem = Foo(42)  # Fine
ipsum = Foo('')  # Expected type 'int', got 'str' instead

However, PyCharm is giving me a warning about @bar.validator (this is a known bug):

Unresolved attribute reference 'validator' for class 'int'

I don't want to define module-level functions, nor can I stuff everything into lambdas. What other (Pythonic) choices do I have?