Add link.
diff --git a/Doc/whatsnew/3.1.rst b/Doc/whatsnew/3.1.rst
index 7e15059..951e678 100644
--- a/Doc/whatsnew/3.1.rst
+++ b/Doc/whatsnew/3.1.rst
@@ -88,7 +88,7 @@
returns an ordered dictionary with the values appearing in the same order as
the underlying tuple indicies. The :mod:`json` module is being built-out with
an *object_pairs_hook* to allow OrderedDicts to be built by the decoder.
-Support was also added for third-party tools like PyYAML.
+Support was also added for third-party tools like `PyYAML <http://pyyaml.org/>`_.
.. seealso::