--- a/ant/build.xml
+++ b/ant/build.xml
@@ -166,6 +166,7 @@
       windowtitle="JCommon Class Library (version ${jcommon.version})"
       overview="source/overview.html"
       linksource="true">
+      <link href="/usr/share/doc/default-jdk-doc/api/" />
       <classpath refid="build-xml.classpath"/>
       <packageset dir="source" defaultexcludes="yes">
         <include name="org/jfree"/>
