diff --git a/documentation/ref-manual/ref-features.xml b/documentation/ref-manual/ref-features.xml
index f5641c69ac..6f5dc00132 100644
--- a/documentation/ref-manual/ref-features.xml
+++ b/documentation/ref-manual/ref-features.xml
@@ -177,6 +177,8 @@
                     supports it.</para></listitem>
                 <listitem><para><emphasis>wifi:</emphasis> Include WiFi support
                     (integrated only).</para></listitem>
+                <listitem><para><emphasis>x11:</emphasis> Include the X server
+                    and libraries.</para></listitem>
             </itemizedlist>
         </para>
     </section>