diff --git a/stdlib/@python2/abc.pyi b/stdlib/@python2/abc.pyi
index 0bf046a4d..ac14246d4 100644
--- a/stdlib/@python2/abc.pyi
+++ b/stdlib/@python2/abc.pyi
@@ -1,4 +1,5 @@
 import _weakrefset
+from _typeshed import SupportsWrite
 from typing import Any, Callable, Dict, Set, Tuple, Type, TypeVar
 
 _FuncT = TypeVar("_FuncT", bound=Callable[..., Any])
@@ -8,17 +9,16 @@ _FuncT = TypeVar("_FuncT", bound=Callable[..., Any])
 def abstractmethod(funcobj: _FuncT) -> _FuncT: ...
 
 class ABCMeta(type):
-    # TODO: FrozenSet
-    __abstractmethods__: Set[Any]
+    __abstractmethods__: frozenset[str]
     _abc_cache: _weakrefset.WeakSet[Any]
     _abc_invalidation_counter: int
     _abc_negative_cache: _weakrefset.WeakSet[Any]
     _abc_negative_cache_version: int
     _abc_registry: _weakrefset.WeakSet[Any]
-    def __init__(self, name: str, bases: Tuple[type, ...], namespace: Dict[Any, Any]) -> None: ...
+    def __init__(self, name: str, bases: Tuple[type, ...], namespace: Dict[str, Any]) -> None: ...
     def __instancecheck__(cls: ABCMeta, instance: Any) -> Any: ...
     def __subclasscheck__(cls: ABCMeta, subclass: Any) -> Any: ...
-    def _dump_registry(cls: ABCMeta, *args: Any, **kwargs: Any) -> None: ...
+    def _dump_registry(cls: ABCMeta, file: SupportsWrite[Any] | None = ...) -> None: ...
     def register(cls: ABCMeta, subclass: Type[Any]) -> None: ...
 
 # TODO: The real abc.abstractproperty inherits from "property".
diff --git a/stdlib/abc.pyi b/stdlib/abc.pyi
index 5dd21763a..bf98d5364 100644
--- a/stdlib/abc.pyi
+++ b/stdlib/abc.pyi
@@ -1,10 +1,16 @@
-from typing import Any, Callable, Type, TypeVar
+from _typeshed import SupportsWrite
+from typing import Any, Callable, Dict, Tuple, Type, TypeVar
 
 _T = TypeVar("_T")
 _FuncT = TypeVar("_FuncT", bound=Callable[..., Any])
 
 # These definitions have special processing in mypy
 class ABCMeta(type):
+    __abstractmethods__: frozenset[str]
+    def __init__(self, name: str, bases: Tuple[type, ...], namespace: Dict[str, Any]) -> None: ...
+    def __instancecheck__(cls: ABCMeta, instance: Any) -> Any: ...
+    def __subclasscheck__(cls: ABCMeta, subclass: Any) -> Any: ...
+    def _dump_registry(cls: ABCMeta, file: SupportsWrite[str] | None = ...) -> None: ...
     def register(cls: ABCMeta, subclass: Type[_T]) -> Type[_T]: ...
 
 def abstractmethod(funcobj: _FuncT) -> _FuncT: ...