Self as return type annotation in overloads raises error

[uriyyo]

Bug Report
Self as return type annotation in overloads raises error.

To Reproduce

from typing import Generic, TypeVar, Any, overload, Literal, Self

T = TypeVar("T", bound=Any)


class MyMapping(Generic[T]):
    @overload
    def get(self, obj: Literal[None]) -> Self:
        pass

    @overload
    def get(self, obj: Any) -> T:
        pass

    def get(self, obj: Any | None) -> T | Self:
        return self

Expected Behavior
No error.

Actual Behavior

error: Overloaded function signatures 1 and 2 overlap with incompatible return types

pyright doesn't raise an error.

Old-style Self approach works as expected:

from __future__ import annotations
from typing import Generic, TypeVar, Any, overload, Literal

T = TypeVar("T", bound=Any)
_Self = TypeVar("_Self", bound="MyMapping[Any]")


class MyMapping(Generic[T]):
    @overload
    def get(self: _Self, obj: Literal[None]) -> _Self:
        pass

    @overload
    def get(self, obj: Any) -> T:
        pass

    def get(self, obj: Any | None) -> T | MyMapping[T]:
        return self

Your Environment

• Mypy version used: 1.0.0
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: 3.11