Index: /applications/editors/josm/plugins/build-common.xml
===================================================================
--- /applications/editors/josm/plugins/build-common.xml	(revision 34361)
+++ /applications/editors/josm/plugins/build-common.xml	(revision 34362)
@@ -230,4 +230,5 @@
             <doctitle><![CDATA[<h2>JOSM-${ant.project.name} - Javadoc</h2>]]></doctitle>
             <bottom><![CDATA[<a href="https://josm.openstreetmap.de/wiki/Plugins">JOSM Plugins</a>]]></bottom>
+            <arg value="-html5" if:set="isJava9" />
             <arg value="--add-exports" if:set="isJava9" />
             <arg value="javafx.graphics/com.sun.javafx.application=ALL-UNNAMED" if:set="isJava9" />