Update ChangeLog for 3.3.1.
diff --git a/ChangeLog b/ChangeLog
index bf96306..fc096d8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,7 +6,10 @@
     http://www.canonware.com/cgi-bin/gitweb.cgi?p=jemalloc.git
     git://canonware.com/jemalloc.git
 
-* 3.x.x (XXX Not yet released)
+* 3.3.1 (March 6, 2013)
+
+  This version fixes bugs that are typically encountered only when utilizing
+  custom run-time options.
 
   Bug fixes:
   - Fix a locking order bug that could cause deadlock during fork if heap
@@ -29,6 +32,7 @@
       array (very unlikely) resulted in memory corruption.
   - Fix Valgrind integration to annotate all internally allocated memory in a
     way that keeps Valgrind happy about internal data structure access.
+  - Fix building for s390 systems.
 
 * 3.3.0 (January 23, 2013)