Index: head/devel/arpc/Makefile
===================================================================
--- head/devel/arpc/Makefile	(revision 486021)
+++ head/devel/arpc/Makefile	(revision 486022)
@@ -1,34 +1,35 @@
 # Created by: Ed Schouten <ed@FreeBSD.org>
 # $FreeBSD$
 
 PORTNAME=	arpc
 DISTVERSIONPREFIX=	v
 DISTVERSION=	0.7
 CATEGORIES=	devel
 
 MAINTAINER=	ed@FreeBSD.org
 COMMENT=	GRPC-like RPC library that supports file descriptor passing
 
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pyPEG2>=2.15.2:textproc/py-pyPEG2@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}toposort>=1.5:devel/py-toposort@${PY_FLAVOR}
 LIB_DEPENDS=	libargdata.so:devel/argdata
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pyPEG2>=2.15.2:textproc/py-pyPEG2@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}toposort>=1.5:devel/py-toposort@${PY_FLAVOR}
 
-USES=		cmake localbase:ldflags python:3.4+ shebangfix
+USES=		compiler:c++17-lang cmake localbase:ldflags python:3.4+ \
+		shebangfix
 SHEBANG_FILES=	scripts/aprotoc.py
 USE_LDCONFIG=	yes
 USE_GITHUB=	yes
 GH_ACCOUNT=	NuxiNL
 
 PLIST_FILES=	bin/aprotoc include/arpc++/arpc++.h \
 		lib/libarpc.so lib/libarpc.so.1
 
 # Require the unit tests to pass prior to installing.
 post-build:
 	@trap '' PIPE && ${WRKSRC}/arpc_tests
 
 .include <bsd.port.mk>