doc update: fix links
diff --git a/documentation/index.rst b/documentation/index.rst
index 5ed0ba1..a5eb155 100644
--- a/documentation/index.rst
+++ b/documentation/index.rst
@@ -16,6 +16,7 @@
 - This page, when viewed online is at https://pyserial.readthedocs.org/en/latest/ or
   http://pythonhosted.org/pyserial/ .
 
+.. _Python: http://python.org/
 .. _`project page on GitHub`: https://github.com/pyserial/
 .. _`Download Page`: http://pypi.python.org/pypi/pyserial
 
diff --git a/documentation/pyserial_api.rst b/documentation/pyserial_api.rst
index 4d7f3ba..5464b64 100644
--- a/documentation/pyserial_api.rst
+++ b/documentation/pyserial_api.rst
@@ -694,8 +694,8 @@
 
 .. class:: rfc2217.Serial
 
-    This implements a :rfc:`2217` compatible client. Port names are URLs_ in the
-    form: ``rfc2217://<host>:<port>[?<option>[&<option>]]``
+    This implements a :rfc:`2217` compatible client. Port names are :ref:`URL
+    <URLs>` in the form: ``rfc2217://<host>:<port>[?<option>[&<option>]]``
 
     This class API is compatible to :class:`Serial` with a few exceptions: