diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 6ad4785e209..58f057acc15 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -141,6 +141,8 @@ process and user.
 
    Availability: Unix.
 
+   .. versionadded:: 3.2
+
 
 .. function:: chdir(path)
               fchdir(fd)