diff --git a/nashorn/make/build-nasgen.xml b/nashorn/make/build-nasgen.xml
index d98333719bd..003201199f4 100644
--- a/nashorn/make/build-nasgen.xml
+++ b/nashorn/make/build-nasgen.xml
@@ -35,11 +35,10 @@
             <classpath>
                 <pathelement location="${basedir}/jcov2/lib/jcov_j2se_rt.jar"/>
                 <pathelement location="${basedir}/buildtools/nasgen/dist/nasgen.jar"/>
-                <pathelement path="${basedir}/build/classes"/>
                 <pathelement location="${dist.dir}/nasgen.jar"/>
                 <pathelement path="${build.dir}/classes"/>
             </classpath>
-            <jvmarg value="${boot.class.path}"/>
+            <jvmarg value="-Xbootclasspath/p:${basedir}/build/classes"/>
             <arg value="${build.dir}/classes"/>
             <arg value="jdk.nashorn.internal.objects"/>
             <arg value="${build.dir}/classes"/>
@@ -52,8 +51,8 @@
         <java classname="jdk.nashorn.internal.tools.nasgen.Main" fork="true" failonerror="true">
             <classpath>
                 <pathelement location="${basedir}/buildtools/nasgen/dist/nasgen.jar"/>
-                <pathelement path="${basedir}/build/eclipse"/>
             </classpath>
+            <jvmarg value="-Xbootclasspath/p:${basedir}/build/eclipse"/>
             <arg value="${basedir}/build/eclipse"/>
             <arg value="jdk.nashorn.internal.objects"/>
             <arg value="${basedir}/build/eclipse/.nasgentmp"/>