diff --git a/ChangeLog b/ChangeLog
index 1672bdf07..d1b2e407e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 1.3.x released xxxx-xx-xx
+
+Security
+
+   * Tighten should-be-constant-time memcmp against compiler optimizations.
+
 = mbed TLS 1.3.20 released 2017-06-21
 
 Security