diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 522316c28e..b47bf529a2 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -270,6 +270,6 @@
 
  &biblio;
  <![%include-index;[&bookindex;]]>
- <![%include-xslt-index;[<index></index>]]>
+ <![%include-xslt-index;[<index id="bookindex"></index>]]>
 
 </book>