diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 6b6e62a683ab18..2af61f2960cc63 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -4986,6 +4986,9 @@ 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