diff --git a/xdoc/src/plugin-resources/sitemap.jsl b/xdoc/src/plugin-resources/sitemap.jsl
index 4fb92082..91ddaaac 100644
--- a/xdoc/src/plugin-resources/sitemap.jsl
+++ b/xdoc/src/plugin-resources/sitemap.jsl
@@ -72,7 +72,7 @@
 
     <jsl:template match="item">
       <x:set var="currentItem" select="." />
-      <x:set var="description" select="null"/>
+      <j:set var="description" value=""/>
       <j:set var="link"><x:expr select="@href"/></j:set>
       <j:if test="${link.startsWith('/')}" trim="yes">
         <j:set var="link" value="${link.substring(1)}"/>