diff --git a/ChangeLog b/ChangeLog
index 47ede8db3..094d712f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 2.1.x released xxxx-xx-xx
+
+Security
+
+   * Tighten should-be-constant-time memcmp against compiler optimizations.
+
 = mbed TLS 2.1.8 released 2017-06-21
 
 Security