Fix up markup in the deprecation notice.
diff --git a/Doc/library/rexec.rst b/Doc/library/rexec.rst
index b61319f..3bc3fc9 100644
--- a/Doc/library/rexec.rst
+++ b/Doc/library/rexec.rst
@@ -7,7 +7,7 @@
    :deprecated:
    
 .. deprecated:: 2.6
-   The rexec module has been removed in Python 3.0.
+   The :mod:`rexec` module has been removed in Python 3.0.
 
 .. versionchanged:: 2.3
    Disabled module.