diff --git a/nixos/doc/manual/release-notes/rl-2405.section.md b/nixos/doc/manual/release-notes/rl-2405.section.md
index b6af5fc6c3cc..f97e159669e8 100644
--- a/nixos/doc/manual/release-notes/rl-2405.section.md
+++ b/nixos/doc/manual/release-notes/rl-2405.section.md
@@ -233,6 +233,11 @@ The pre-existing [services.ankisyncd](#opt-services.ankisyncd.enable) has been m
 - The option [`services.nextcloud.config.dbport`] of the Nextcloud module was removed to match upstream.
   The port can be specified in [`services.nextcloud.config.dbhost`](#opt-services.nextcloud.config.dbhost).
 
+- A new abstraction to create both read-only as well as writable overlay file
+  systems was added. Available via
+  [fileSystems.overlay](#opt-fileSystems._name_.overlay.lowerdir). See also the
+  [NixOS docs](#sec-overlayfs).
+
 - `stdenv`: The `--replace` flag in `substitute`, `substituteInPlace`, `substituteAll`, `substituteAllStream`, and `substituteStream` is now deprecated if favor of the new `--replace-fail`, `--replace-warn` and `--replace-quiet`. The deprecated `--replace` equates to `--replace-warn`.
 
 - New options were added to the dnsdist module to enable and configure a DNSCrypt endpoint (see `services.dnsdist.dnscrypt.enable`, etc.).