diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 8d92ac3957c8a5..c872ba5840c74e 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -4749,6 +4749,9 @@ written in Python, such as a mail server's external command delivery program.
 
    .. availability:: Unix, not Emscripten, not WASI.
 
+   .. note::
+      This function is not available on macOS.
+
    .. versionadded:: 3.3