diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst
index 3f68932..0aadad3 100644
--- a/Doc/tutorial/modules.rst
+++ b/Doc/tutorial/modules.rst
@@ -249,7 +249,7 @@
   directory.
 
 * There is more detail on this process, including a flow chart of the
-  decisions, in PEP 3147.
+  decisions, in :pep:`3147`.
 
 
 .. _tut-standardmodules: