diff --git a/nixos/doc/manual/release-notes/rl-2305.section.md b/nixos/doc/manual/release-notes/rl-2305.section.md
index c8f600bf7bb3..54b410ffd826 100644
--- a/nixos/doc/manual/release-notes/rl-2305.section.md
+++ b/nixos/doc/manual/release-notes/rl-2305.section.md
@@ -190,6 +190,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - Calling `makeSetupHook` without passing a `name` argument is deprecated.
 
+- Top-level buildPlatform,hostPlatform,targetPlatform have been deprecated, use stdenv.X instead.
+
 - `lib.systems.examples.ghcjs` and consequently `pkgsCross.ghcjs` now use the target triplet `javascript-unknown-ghcjs` instead of `js-unknown-ghcjs`. This has been done to match an [upstream decision](https://gitlab.haskell.org/ghc/ghc/-/commit/6636b670233522f01d002c9b97827d00289dbf5c) to follow Cabal's platform naming more closely. Nixpkgs will also reject `js` as an architecture name.
 
 - `dokuwiki` has been updated from 2023-07-31a (Igor) to 2023-04-04 (Jack Jackrum), which has [completely removed](https://www.dokuwiki.org/changes#release_2023-04-04_jack_jackrum) the options to embed HTML and PHP for security reasons. The [htmlok plugin](https://www.dokuwiki.org/plugin:htmlok) can be used to regain this functionality.