diff --git a/ChangeLog.d/constant_time_module.txt b/ChangeLog.d/constant_time_module.txt
index 5e76deaa8..ebb0b7fb9 100644
--- a/ChangeLog.d/constant_time_module.txt
+++ b/ChangeLog.d/constant_time_module.txt
@@ -1,6 +1,10 @@
 Changes
-    * The mbedcrypto library includes new a source code module constant_time.c,
+    * The mbedcrypto library includes a new source code module constant_time.c,
       containing various functions meant to resist timing side channel attacks.
       This module does not have a separate configuration option, and functions
       from this module will be included in the build as required. Currently
-      the interface of this module is private and may change at any time.
+      most of the interface of this module is private and may change at any
+      time.
+
+Features
+    * Add new API mbedtls_ct_memcmp for constant time buffer comparison.