false positive Incompatible types in assignment for overloaded function

[sam-s]

I declare a variable type and get assignment error for gzip.open but not for open,

To Reproduce

from collections.abc import Callable
from typing import IO
import gzip

foo : Callable[[str, str], IO] = gzip.open

Expected Behavior

no diagnostics

Actual Behavior

error: Incompatible types in assignment (expression has type overloaded function, variable has type "Callable[[str, str], IO[Any]]") [assignment]

but no diagnostics for

from collections.abc import Callable
from typing import IO

foo : Callable[[str, str], IO] = open

Your Environment

• Mypy version used: mypy 2.3.0
• Mypy command-line flags: --check-untyped-defs
• Python version used: 3.14.6