Index: head/biology/treekin/Makefile
===================================================================
--- head/biology/treekin/Makefile	(revision 506913)
+++ head/biology/treekin/Makefile	(revision 506914)
@@ -1,28 +1,29 @@
 # $FreeBSD$
 
 PORTNAME=	treekin
 DISTVERSION=	0.5.1
 CATEGORIES=	biology
 MASTER_SITES=	https://www.tbi.univie.ac.at/RNA/packages/source/
 DISTNAME=	Treekin-${DISTVERSION}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Efficient computation of RNA folding dynamics
 
 LICENSE=	LatticeLib
 LICENSE_NAME=	LatticeLib Disclaimer and Copyright
 LICENSE_FILE=	${WRKSRC}/COPYING
 LICENSE_PERMS=	auto-accept dist-mirror pkg-mirror
 
 BUILD_DEPENDS=	lapacke>0:math/lapacke
 
-USES=		blaslapack:netlib fortran gmake localbase:ldflags
+USES=		blaslapack:netlib compiler:c++11-lang fortran gmake \
+		localbase:ldflags
 
 GNU_CONFIGURE=	yes
 
 BINARY_ALIAS=	make=${GMAKE}
 
 PLIST_FILES=	bin/${PORTNAME} \
 		man/man1/${PORTNAME}.1.gz
 
 .include <bsd.port.mk>