More source links
diff --git a/Doc/library/xdrlib.rst b/Doc/library/xdrlib.rst
index 4fcb9cd..1d3da0a 100644
--- a/Doc/library/xdrlib.rst
+++ b/Doc/library/xdrlib.rst
@@ -9,6 +9,10 @@
single: XDR
single: External Data Representation
+**Source code:** :source:`Lib/xdrlib.py`
+
+--------------
+
The :mod:`xdrlib` module supports the External Data Representation Standard as
described in :rfc:`1014`, written by Sun Microsystems, Inc. June 1987. It
supports most of the data types described in the RFC.