diff --git a/doc/release-notes.md b/doc/release-notes.md
index 2b22a69..9eb0767 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -1,3 +1,12 @@
+0.16.4
+==============
+
+- Security: Always require the initiate tx output index and value for secret hash swaps.
+  - Strengthens the 0.16.3 fix: the amount check can no longer be skipped when the output value is unavailable; the swap is now rejected (fails closed) instead of proceeding.
+- Security: Also verify the participate tx output amount for secret hash swaps.
+- Raise minimum Python version to 3.11.
+
+
 0.16.3
 ==============