diff --git a/build.xml b/build.xml
index beb50c46a..9c0107a80 100644
--- a/build.xml
+++ b/build.xml
@@ -241,6 +241,8 @@
 	    </classpath>
 	    <option value="-Xms256M"/>
 	    <option value="-Xmx1024M"/>
+	    <option value="-Djava.awt.headless=true"/>
+	    <option value="-Drefine.headless=true"/>
 	    <option value="-Drefine.version=${revision}"/>
 	    <option value="-Drefine.webapp=$APP_ROOT/Contents/Resource/${built.webapp.name}"/>
         </bundleapp>