Index: head/math/sisl/Makefile
===================================================================
--- head/math/sisl/Makefile	(revision 519589)
+++ head/math/sisl/Makefile	(revision 519590)
@@ -1,26 +1,26 @@
 # $FreeBSD$
 
 PORTNAME=	sisl
 DISTVERSIONPREFIX=	SISL-
 DISTVERSION=	4.6.0-44
 DISTVERSIONSUFFIX=	-g9114631
 CATEGORIES=	math
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Spline library
 
 LICENSE=	GPLv3
 LICENSE_FILE=	${WRKSRC}/COPYING
 
-USES=		cmake
+USES=		cmake compiler:c++11-lang
 USE_GITHUB=	yes
 GH_ACCOUNT=	SINTEF-Geometry
 GH_PROJECT=	SISL
 USE_LDCONFIG=	yes
 
 PLIST_FILES=	include/sisl-copyright.h \
 		include/sisl.h \
 		include/sislP.h \
 		lib/libsisl.so
 
 .include <bsd.port.mk>