Return old hack, because new break mypy plugins :face_with_rolling_eyes:

aiogram/dispatcher/filters/base.py

@@ -1,26 +1,28 @@
 from abc import ABC, abstractmethod
 from typing import (
-    Awaitable,
-    Callable,
+    TYPE_CHECKING,
     Any,
     Dict,
     Union,
+    Callable,
+    Awaitable,
 )
 
 from pydantic import BaseModel
 
 
-async def _call_for_override(*args: Any, **kwargs: Any) -> Union[bool, Dict[str, Any]]:  # pragma: no cover
-    pass
-
-
 class BaseFilter(ABC, BaseModel):
-    # This little hack with typehint is needed because mypy checks validity of overrides and raises:
-    # error: Signature of "__call__" incompatible with supertype "BaseFilter"  [override]
-    # https://mypy.readthedocs.io/en/latest/error_code_list.html#check-validity-of-overrides-override
-    __call__: Callable[..., Awaitable[Union[bool, Dict[str, Any]]]] = _call_for_override
-    abstractmethod(__call__)
+    if TYPE_CHECKING:  # pragma: no cover
+        # This checking type-hint is needed because mypy checks validity of overrides and raises:
+        # error: Signature of "__call__" incompatible with supertype "BaseFilter"  [override]
+        # https://mypy.readthedocs.io/en/latest/error_code_list.html#check-validity-of-overrides-override
+        __call__: Callable[..., Awaitable[Union[bool, Dict[str, Any]]]]
+    else:  # pragma: no cover
 
-    def __await__(self):  # type: ignore  # pragma: no cover
+        @abstractmethod
+        async def __call__(self, *args: Any, **kwargs: Any) -> Union[bool, Dict[str, Any]]:
+            pass
+
+    def __await__(self):  # type: ignore # pragma: no cover
         # Is needed only for inspection and this method is never be called
         return self.__call__