diff --git a/nixos/doc/manual/from_md/release-notes/rl-2211.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2211.section.xml
index 59f953d49169..8b79b09a8b38 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2211.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2211.section.xml
@@ -814,6 +814,15 @@
           <literal>nix.checkConfig</literal> previously did.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <literal>nix.buildMachines</literal> got a new submodule
+          option <literal>protocol</literal>. An undocumented hack to
+          set the protocol via <literal>hostName</literal> is no longer
+          working and the <literal>protocol</literal> option should be
+          used instead.
+        </para>
+      </listitem>
       <listitem>
         <para>
           <literal>generateOptparseApplicativeCompletions</literal> and
diff --git a/nixos/doc/manual/release-notes/rl-2211.section.md b/nixos/doc/manual/release-notes/rl-2211.section.md
index f283b3c388ea..6d0bc1197768 100644
--- a/nixos/doc/manual/release-notes/rl-2211.section.md
+++ b/nixos/doc/manual/release-notes/rl-2211.section.md
@@ -266,6 +266,8 @@ Available as [services.patroni](options.html#opt-services.patroni.enable).
 
 - The `nix.checkConfig` option now fully disables the config check. The new `nix.checkAllErrors` option behaves like `nix.checkConfig`  previously did.
 
+- `nix.buildMachines` got a new submodule option `protocol`. An undocumented hack to set the protocol via `hostName` is no longer working and the `protocol` option should be used instead.
+
 - `generateOptparseApplicativeCompletions` and `generateOptparseApplicativeCompletion` from `haskell.lib.compose`
   (and `haskell.lib`) have been deprecated in favor of `generateOptparseApplicativeCompletions` (plural!) as
   provided by the haskell package sets (so `haskellPackages.generateOptparseApplicativeCompletions` etc.).