diff --git a/doc/reference/docbook.build b/doc/reference/docbook.build
index 2e06bf64..4f6255c2 100644
--- a/doc/reference/docbook.build
+++ b/doc/reference/docbook.build
@@ -17,7 +17,8 @@
     <echo message="project.basedir = ${project.basedir}"/>
     <echo message="project.targetdir = ${project.targetdir}"/>
   </target>
-  <target name="all" depends="html,html-help,pdf"/>
+  
+  <target name="all" depends="html,pdf,html-help"/>
 
   <target name="html">
     <echo message="Generating HTML format..." />