diff --git a/ChangeLog b/ChangeLog
index fe5ce65..c9d5ec0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 2.1.x branch released xxxx-xx-xx
+
+Bugfix
+   * Fixed issue in mutexes to failing to initialise. #667
+
 = mbed TLS 2.1.7 branch released 2017-03-08
 
 Security