diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index d71378d271..49632365d2 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -4860,6 +4860,10 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
                         <listitem><para><emphasis><filename>striplevel</filename> -</emphasis> Which
                             striplevel to use when applying the patch.
                             The default level is 1.</para></listitem>
+                        <listitem><para><emphasis><filename>patchdir</filename> -</emphasis> Specifies
+                            the directory in which the patch should be applied.
+                            The default is <filename>${</filename><link linkend='var-S'><filename>S</filename></link><filename>}</filename>.
+                            </para></listitem>
                     </itemizedlist>
                 </para>
                 <para>Here are options specific to recipes building code from a revision control system: