diff --git a/ChangeLog b/ChangeLog
index 513f24f..9a56ed8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,8 @@
    * 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.
+   * Improve documentation of mbedtls_ssl_get_verify_result().
+     Fixes #517 reported by github-monoculture.
 
 = mbed TLS 2.13.1 branch released 2018-09-06