diff --git a/docs/dhcp.xml b/docs/dhcp.xml
index 640af8c64..d5a89bfce 100644
--- a/docs/dhcp.xml
+++ b/docs/dhcp.xml
@@ -73,7 +73,7 @@
       <listitem>
         <para>If you set 'ping-check' true in your
         <filename>/etc/shorewall/dhcpd.conf</filename> file then you will want
-        to <ulink url="ping.htm">accept 'ping'</ulink> from your firewall to
+        to <ulink url="ping.html">accept 'ping'</ulink> from your firewall to
         the zone(s) served by the firewall's DHCP server.</para>
       </listitem>
     </itemizedlist>
@@ -116,10 +116,10 @@
       </listitem>
 
       <listitem>
-        <para>It is a good idea to <ulink url="ping.htm">accept 'ping'</ulink>
-        on any interface that gets its IP address via DHCP. That way, if the
-        DHCP server is configured with 'ping-check' true, you won't be
-        blocking its 'ping' requests.</para>
+        <para>It is a good idea to <ulink url="ping.html">accept
+        'ping'</ulink> on any interface that gets its IP address via DHCP.
+        That way, if the DHCP server is configured with 'ping-check' true, you
+        won't be blocking its 'ping' requests.</para>
       </listitem>
     </itemizedlist>
   </section>
@@ -168,8 +168,8 @@ DHCPfwd(ACCEPT) ZONEA         ZONEB</programlisting>
 
       <listitem>
         <para>If the server is configured with 'ping-check' true, then you
-        must <ulink url="ping.htm">allow 'ping'</ulink> from the server's zone
-        to the zone(s) served by dhcrelay.</para>
+        must <ulink url="ping.html">allow 'ping'</ulink> from the server's
+        zone to the zone(s) served by dhcrelay.</para>
       </listitem>
     </itemizedlist>
   </section>