diff --git a/ChangeLog b/ChangeLog
index 978b8b5cd..b1117c696 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,17 @@ mbed TLS ChangeLog (Sorted per branch, date)
 
 = mbed TLS 2.x.x branch released xxxx-xx-xx
 
+Features
+   * Add support for draft-05 of the Connection ID extension, as specified
+     in https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05.
+     The Connection ID extension allows to keep DTLS connections beyond the
+     lifetime of the underlying transport by adding a connection identifier
+     to the DTLS record header. This identifier can be used to associated an
+     incoming record with the correct connection data even after the peer has
+     changed its IP or port. The feature is enabled at compile-time by setting
+     MBEDTLS_SSL_DTLS_CONNECTION_ID (disabled by default), and at run-time
+     through the new APIs mbedtls_ssl_conf_cid() and mbedtls_ssl_set_cid().
+
 Security
    * Make mbedtls_ecdh_get_params return an error if the second key
      belongs to a different group from the first. Before, if an application