Adapt ChangeLog
diff --git a/ChangeLog b/ChangeLog
index 341ae91..14a9114 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -44,6 +44,11 @@
      to bypass the version verification check. Found by Peng Li/Yueh-Hsun Lin,
      KNOX Security, Samsung Research America
 
+Changes
+   * Avoid shadowing of time and index functions through mbed TLS function
+     arguments. Found by inestlerode. Fixes #557.
+
+
 = mbed TLS 1.3.20 branch released 2017-06-21
 
 Security