diff --git a/stdlib/ntpath.pyi b/stdlib/ntpath.pyi
index 4ee1b31c6..bcd58b532 100644
--- a/stdlib/ntpath.pyi
+++ b/stdlib/ntpath.pyi
@@ -52,18 +52,10 @@ def normcase(s: AnyStr) -> AnyStr: ...
 def normpath(path: PathLike[AnyStr]) -> AnyStr: ...
 @overload
 def normpath(path: AnyStr) -> AnyStr: ...
-
-if sys.platform == "win32":
-    @overload
-    def realpath(path: PathLike[AnyStr]) -> AnyStr: ...
-    @overload
-    def realpath(path: AnyStr) -> AnyStr: ...
-
-else:
-    @overload
-    def realpath(filename: PathLike[AnyStr]) -> AnyStr: ...
-    @overload
-    def realpath(filename: AnyStr) -> AnyStr: ...
+@overload
+def realpath(path: PathLike[AnyStr]) -> AnyStr: ...
+@overload
+def realpath(path: AnyStr) -> AnyStr: ...
 
 # In reality it returns str for sequences of StrPath and bytes for sequences
 # of BytesPath, but mypy does not accept such a signature.
diff --git a/stdlib/os/__init__.pyi b/stdlib/os/__init__.pyi
index 98f078be8..1122bfabf 100644
--- a/stdlib/os/__init__.pyi
+++ b/stdlib/os/__init__.pyi
@@ -712,7 +712,7 @@ if sys.platform != "win32":
         ) -> Iterator[Tuple[str, List[str], List[str], int]]: ...
     if sys.platform == "linux":
         def getxattr(path: _FdOrAnyPath, attribute: AnyPath, *, follow_symlinks: bool = ...) -> bytes: ...
-        def listxattr(path: _FdOrAnyPath, *, follow_symlinks: bool = ...) -> List[str]: ...
+        def listxattr(path: Optional[_FdOrAnyPath] = ..., *, follow_symlinks: bool = ...) -> List[str]: ...
         def removexattr(path: _FdOrAnyPath, attribute: AnyPath, *, follow_symlinks: bool = ...) -> None: ...
         def setxattr(
             path: _FdOrAnyPath, attribute: AnyPath, value: bytes, flags: int = ..., *, follow_symlinks: bool = ...
diff --git a/tests/stubtest_whitelists/linux.txt b/tests/stubtest_whitelists/linux.txt
index 3fc064b1a..e96488798 100644
--- a/tests/stubtest_whitelists/linux.txt
+++ b/tests/stubtest_whitelists/linux.txt
@@ -1,15 +1,14 @@
 _posixsubprocess.cloexec_pipe
 _?curses.ACS_.* # ACS codes are initialized only after initscr call. 
-curses.COLORS
-curses.COLOR_PAIRS
-curses.COLS
-curses.LINES
+curses.COLORS  # Initialized after start_color
+curses.COLOR_PAIRS  # Initialized after start_color
+curses.COLS  # Initialized only after initscr call. 
+curses.LINES  # Initialized only after initscr call. 
 distutils.command.bdist_msi  # msi is only available on windows
 grp.getgrgid
 grp.struct_group._asdict
 grp.struct_group._make
 grp.struct_group._replace
-ntpath.realpath
 os.EX_NOTFOUND
 os.SF_MNOWAIT
 os.SF_NODISKIO
@@ -17,7 +16,6 @@ os.SF_SYNC
 os.chflags
 os.lchflags
 os.lchmod
-os.listxattr
 os.plock
 posix.EX_NOTFOUND
 select.EPOLL_RDHUP