diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index cbe008fe734452..8565fab44114db 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -1125,6 +1125,8 @@ always available.
    *pyc_magic_number* is the magic number used to identify that cached ``.pyc``
    files match the running version of Python.
 
+   .. versionadded:: 3.14
+
    :data:`sys.implementation` may contain additional attributes specific to
    the Python implementation.  These non-standard attributes must start with
    an underscore, and are not described here.  Regardless of its contents,