diff --git a/ChangeLog b/ChangeLog
index 348864c..1e5d73d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -54,6 +54,10 @@
      This function is necessary to determine when it is safe to idle on the
      underlying transport in case event-driven IO is used.
 
+Features
+    * Implement the HMAC-based extract-and-expand key derivation function
+      (HKDF) per RFC 5869. Contributed by Thomas Fossati.
+
 Bugfix
    * Fix a spurious uninitialized variable warning in cmac.c. Fix independently
      contributed by Brian J Murray and David Brown.