diff --git a/docs/two-interface.xml b/docs/two-interface.xml
index 0d17375c6..7153d39ce 100644
--- a/docs/two-interface.xml
+++ b/docs/two-interface.xml
@@ -756,7 +756,7 @@ DNAT       net       loc:10.10.10.2:80  tcp       5000</programlisting>
   </section>
 
   <section id="DNS">
-    <title>DDomain Name Server (DNS)</title>
+    <title>Domain Name Server (DNS)</title>
 
     <para>Normally, when you connect to your ISP, as part of getting an IP
     address your firewall's <emphasis>Domain Name Service</emphasis>