diff --git a/en_US.ISO8859-1/books/handbook/book.sgml b/en_US.ISO8859-1/books/handbook/book.sgml
index cb7ffccec5..e3a431267d 100644
--- a/en_US.ISO8859-1/books/handbook/book.sgml
+++ b/en_US.ISO8859-1/books/handbook/book.sgml
@@ -33,6 +33,7 @@
 <!ENTITY % chap.serialcomms "IGNORE">
 <!ENTITY % chap.ppp-and-slip "IGNORE">
 <!ENTITY % chap.advanced-networking "IGNORE">
+<!ENTITY % chap.firewalls "IGNORE">
 <!ENTITY % chap.network-servers "IGNORE">
 <!ENTITY % chap.mail "IGNORE">
 <!ENTITY % chap.cutting-edge "IGNORE">