diff --git a/doc/cookbook/events.xml b/doc/cookbook/events.xml
index dbb76c4b5..65694a3ab 100644
--- a/doc/cookbook/events.xml
+++ b/doc/cookbook/events.xml
@@ -1,7 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
 
-<chapter id="events">
+<chapter id="events" xmlns:xi="http://www.w3.org/2003/XInclude">
   <title>Events</title>
 
   <epigraph>