diff --git a/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml
index 59da373f38e1..58b7c1e802d1 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml
@@ -1429,6 +1429,17 @@ Superuser created successfully.
           knob.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <literal>/usr</literal> will always be included in the initial
+          ramdisk. See the
+          <literal>fileSystems.&lt;name&gt;.neededForBoot</literal>
+          option. If any files exist under <literal>/usr</literal>
+          (which is not typical for NixOS), they will be included in the
+          initial ramdisk, increasing its size to a possibly problematic
+          extent.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
   <section xml:id="sec-release-21.11-notable-changes">
diff --git a/nixos/doc/manual/release-notes/rl-2111.section.md b/nixos/doc/manual/release-notes/rl-2111.section.md
index 1b59842e020b..6fe838d1e7a5 100644
--- a/nixos/doc/manual/release-notes/rl-2111.section.md
+++ b/nixos/doc/manual/release-notes/rl-2111.section.md
@@ -419,6 +419,9 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - The Linux kernel for security reasons now restricts access to BPF syscalls via `BPF_UNPRIV_DEFAULT_OFF=y`. Unprivileged access can be reenabled via the `kernel.unprivileged_bpf_disabled` sysctl knob.
 
+- `/usr` will always be included in the initial ramdisk. See the `fileSystems.<name>.neededForBoot` option.
+  If any files exist under `/usr` (which is not typical for NixOS), they will be included in the initial ramdisk, increasing its size to a possibly problematic extent.
+
 ## Other Notable Changes {#sec-release-21.11-notable-changes}