diff --git a/stdlib/_socket.pyi b/stdlib/_socket.pyi
index df6b45a2d394..f7b0e6901bf4 100644
--- a/stdlib/_socket.pyi
+++ b/stdlib/_socket.pyi
@@ -583,7 +583,11 @@ class socket:
     def proto(self) -> int: ...
     @property
     def timeout(self) -> float | None: ...
-    def __init__(self, family: int = ..., type: int = ..., proto: int = ..., fileno: _FD | None = ...) -> None: ...
+    if sys.platform == "win32":
+        def __init__(self, family: int = ..., type: int = ..., proto: int = ..., fileno: _FD | bytes | None = ...) -> None: ...
+    else:
+        def __init__(self, family: int = ..., type: int = ..., proto: int = ..., fileno: _FD | None = ...) -> None: ...
+
     def bind(self, __address: _Address) -> None: ...
     def close(self) -> None: ...
     def connect(self, __address: _Address) -> None: ...