Index: head/audio/synthv1-lv2/Makefile
===================================================================
--- head/audio/synthv1-lv2/Makefile	(revision 502159)
+++ head/audio/synthv1-lv2/Makefile	(revision 502160)
@@ -1,30 +1,31 @@
 # $FreeBSD$
 
 PORTNAME=	synthv1
 DISTVERSIONPREFIX=	${PORTNAME}_
 DISTVERSION=	0_9_7
 CATEGORIES=	audio
 PKGNAMESUFFIX=	-lv2
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Old-school polyphonic synthesizer
 
 LICENSE=	GPLv2
 LICENSE_FILE=	${WRKSRC}/COPYING
 
 BUILD_DEPENDS=	lv2>0:audio/lv2
 LIB_DEPENDS=	libjack.so:audio/jack \
 		liblo.so:audio/liblo
 
-USES=		autoreconf gl gmake pkgconfig qt:5 shared-mime-info
+USES=		autoreconf compiler:c++11-lang gl gmake pkgconfig qt:5 \
+		shared-mime-info
 GNU_CONFIGURE=	yes
 USE_GITHUB=	yes
 GH_ACCOUNT=	rncbc
 USE_GL=		gl
 USE_QT=		core gui widgets xml buildtools_build qmake_build
 
 PLIST_SUB=	SHL3=${PORTVERSION} SHL2=${PORTVERSION:R}
 
 CONFIGURE_ARGS=	--disable-alsa-midi
 
 .include <bsd.port.mk>