diff --git a/stdlib/winreg.pyi b/stdlib/winreg.pyi
index 53457112ee96..a654bbcdfb61 100644
--- a/stdlib/winreg.pyi
+++ b/stdlib/winreg.pyi
@@ -18,13 +18,13 @@ if sys.platform == "win32":
     def ExpandEnvironmentStrings(string: str, /) -> str: ...
     def FlushKey(key: _KeyType, /) -> None: ...
     def LoadKey(key: _KeyType, sub_key: str, file_name: str, /) -> None: ...
-    def OpenKey(key: _KeyType, sub_key: str, reserved: int = 0, access: int = 131097) -> HKEYType: ...
-    def OpenKeyEx(key: _KeyType, sub_key: str, reserved: int = 0, access: int = 131097) -> HKEYType: ...
+    def OpenKey(key: _KeyType, sub_key: str | None, reserved: int = 0, access: int = 131097) -> HKEYType: ...
+    def OpenKeyEx(key: _KeyType, sub_key: str | None, reserved: int = 0, access: int = 131097) -> HKEYType: ...
     def QueryInfoKey(key: _KeyType, /) -> tuple[int, int, int]: ...
     def QueryValue(key: _KeyType, sub_key: str | None, /) -> str: ...
     def QueryValueEx(key: _KeyType, name: str, /) -> tuple[Any, int]: ...
     def SaveKey(key: _KeyType, file_name: str, /) -> None: ...
-    def SetValue(key: _KeyType, sub_key: str, type: int, value: str, /) -> None: ...
+    def SetValue(key: _KeyType, sub_key: str | None, type: int, value: str, /) -> None: ...
     @overload  # type=REG_DWORD|REG_QWORD
     def SetValueEx(
         key: _KeyType, value_name: str | None, reserved: Unused, type: Literal[4, 5], value: int | None, /