diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index b6b0b6c..486e475 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -52,7 +52,11 @@
 recent variant that repairs these flaws.
 
 .. versionchanged:: 2.3
-   Substituted MersenneTwister for Wichmann-Hill.
+   MersenneTwister replaced Wichmann-Hill as the default generator.
+
+The :mod:`random` module also provides the :class:`SystemRandom` class which
+uses the system function :func:`os.urandom` to generate random numbers
+from sources provided by the operating system.
 
 Bookkeeping functions: