Fix up markup in the deprecation notice.
diff --git a/Doc/library/mutex.rst b/Doc/library/mutex.rst
index ed0ad92..480c888 100644
--- a/Doc/library/mutex.rst
+++ b/Doc/library/mutex.rst
@@ -7,7 +7,7 @@
    :deprecated:
    
 .. deprecated::
-   The mutex module has been removed in Python 3.0.
+   The :mod:`mutex` module has been removed in Python 3.0.
 
 .. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>