diff --git a/docs/Install.xml b/docs/Install.xml
index 77cde0a70..a19018246 100644
--- a/docs/Install.xml
+++ b/docs/Install.xml
@@ -288,6 +288,15 @@
             pathname for PERLLIB.</para>
           </listitem>
         </varlistentry>
+
+        <varlistentry>
+          <term>MANDIR</term>
+
+          <listitem>
+            <para>Determines where the man pages are installed. Default is
+            distribution-dependent as shown below.</para>
+          </listitem>
+        </varlistentry>
       </variablelist>
     </section>