diff --git a/build.xml b/build.xml
index 6d53e4c..8ff24fb 100644
--- a/build.xml
+++ b/build.xml
@@ -85,6 +85,7 @@ class Version { public static String VERSION = "${VERSION}";}
 		<doclet name="org.umlgraph.doclet.UmlGraphDoc" path="${lib}/UmlGraph.jar">
 			<param name="-inferrel"/>
 			<param name="-inferdep"/>
+			<param name="-collapsible"/>
 			<param name="-hide" value="java.*"/>
 			<param name="-collpackages" value="java.util.*"/>
 			<param name="-qualify"/>