Index: head/math/ntl/Makefile
===================================================================
--- head/math/ntl/Makefile	(revision 480129)
+++ head/math/ntl/Makefile	(revision 480130)
@@ -1,47 +1,47 @@
 # Created by: bauerm
 # $FreeBSD$
 
 PORTNAME=	ntl
 PORTVERSION=	11.3.0
 CATEGORIES=	math
 MASTER_SITES=	http://www.shoup.net/ntl/
 
 MAINTAINER=	ndowens@yahoo.com
 COMMENT=	Victor Shoup's Number Theory Library
 
 LICENSE=	LGPL21+
 LICENSE_FILE=	${WRKSRC}/../doc/copying.txt
 
-USES=		perl5 libtool
+USES=		compiler:c11 libtool perl5
 USE_LDCONFIG=	yes
 USE_PERL5=	build
 HAS_CONFIGURE=	yes
 CONFIGURE_ARGS+=	AR="${AR}" \
 		CXX="${CXX}" CXXFLAGS="${CXXFLAGS}" \
 		DEF_PREFIX="${LOCALBASE}" \
 		LDFLAGS="${LDFLAGS}" PREFIX="${PREFIX}" \
 		RANLIB="${RANLIB}" SHARED=on
 
 CFLAGS+=	-fPIC
 WRKSRC=		${WRKDIR}/${DISTNAME}/src
 MAKEFILE=	makefile
 
 OPTIONS_DEFINE=	DOCS GMP
 OPTIONS_DEFAULT=	GMP
 
 GMP_DESC=		Arbitrary precision arithmetic(Faster)
 GMP_CONFIGURE_OFF=	NTL_GMP_LIP=off
 GMP_LIB_DEPENDS=	libgmp.so:math/gmp
 
 NTLDOCSDIR=		share/doc/NTL
 PLIST_SUB=		NTLDOCS=${NTLDOCSDIR}
 
 do-install-DOCS-on:
 	${MKDIR} ${STAGEDIR}${DOCSDIR}
 	${INSTALL_DATA} ${WRKSRC}/../doc/* ${STAGEDIR}${DOCSDIR}
 
 test: build
 	@(cd ${WRKSRC}; ${SETENV} ${MAKE_ENV} ${MAKE} \
 		${MAKE_FLAGS} ${MAKEFILE} ${MAKE_ARGS} check)
 
 .include <bsd.port.mk>