diff --git a/Doc/library/ctypes.rst b/Doc/library/ctypes.rst
index 12b44569271efc..bc3a50a633f2ff 100644
--- a/Doc/library/ctypes.rst
+++ b/Doc/library/ctypes.rst
@@ -2540,6 +2540,8 @@ fields, or any other data types containing pointer type fields.
       the structure when being packed or unpacked to/from memory.
       Setting this attribute to 0 is the same as not setting it at all.
 
+      .. versionadded:: 3.13
+
    .. attribute:: _anonymous_
 
       An optional sequence that lists the names of unnamed (anonymous) fields.
diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index a47d5e077a357b..565f74149725d5 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -814,6 +814,10 @@ ctypes
   See :gh:`124520` for discussion and links to changes in some affected
   projects.
 
+* :class:`ctypes.Structure` objects have a new :attr:`~ctypes.Structure._align_`
+  attribute which allows the alignment of the structure being packed to/from
+  memory to be specified explicitly.
+  (Contributed by Matt Sanderson in :gh:`112433`)
 
 dbm
 ---