diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 5d68e5a..ce47bd0 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -717,7 +717,7 @@
       >>> p._asdict()
       OrderedDict([('x', 11), ('y', 22)])
 
-   .. versionchanged 3.1
+   .. versionchanged:: 3.1
       Returns an :class:`OrderedDict` instead of a regular :class:`dict`.
 
 .. method:: somenamedtuple._replace(kwargs)