Add ChangeLog entry for PR #1811
diff --git a/ChangeLog b/ChangeLog
index 64dce14..8c82d08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -10,6 +10,9 @@
 
 Changes
    * Add tests for session resumption in DTLS.
+   * Close a test gap in (D)TLS between the client side and the server side:
+     test the handling of large packets and small packets on the client side
+     in the same way as on the server side.
 
 = mbed TLS 2.1.15 branch released 2018-08-31