diff -Naur sbt.org/Makefile sbt/Makefile
--- sbt.org/Makefile	2019-11-28 09:47:03.130697000 +0100
+++ sbt/Makefile	2019-11-28 09:41:09.650311000 +0100
@@ -3,6 +3,7 @@
 
 PORTNAME=	sbt
 PORTVERSION=	1.3.4
+PORTREVISION=	1
 CATEGORIES=	devel java
 MASTER_SITES=	https://github.com/sbt/sbt/releases/download/v${PORTVERSION}/
 
@@ -40,6 +41,7 @@
 do-install:
 	${MKDIR} ${STAGEDIR}${DATADIR}
 	${INSTALL_DATA} ${WRKSRC}/bin/sbt-launch.jar ${STAGEDIR}${DATADIR}
+	${INSTALL_DATA} ${WRKSRC}/bin/java9-rt-export.jar ${STAGEDIR}${DATADIR}
 .if ${PORT_OPTIONS:MADVANCED}
 	${INSTALL_SCRIPT} ${WRKSRC}/bin/sbt ${STAGEDIR}${DATADIR}
 	${MKDIR} ${STAGEDIR}${DATADIR}/conf
@@ -50,6 +52,7 @@
 	${LN} -s ../${DATADIR_REL}/sbt ${STAGEDIR}${PREFIX}/bin/
 .else
 	${INSTALL_DATA} ${WRKSRC}/bin/sbt-launch.jar ${STAGEDIR}${DATADIR}
+	${INSTALL_DATA} ${WRKSRC}/bin/java9-rt-export.jar ${STAGEDIR}${DATADIR}
 	${INSTALL_SCRIPT} ${WRKDIR}/sbt.sh ${STAGEDIR}${PREFIX}/bin/sbt
 .endif