Index: head/math/gh-bc/Makefile
===================================================================
--- head/math/gh-bc/Makefile	(revision 501944)
+++ head/math/gh-bc/Makefile	(revision 501945)
@@ -1,35 +1,36 @@
 # $FreeBSD$
 
 PORTNAME=	bc
 PORTVERSION=	1.2.8
+PORTREVISION=	1
 CATEGORIES=	math
 PKGNAMEPREFIX=	gh-
 
 MAINTAINER=	se@FreeBSD.org
 COMMENT=	GNU compatible bc/dc calculator
 
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE.md
 
-USES=		compiler:c11
 USE_GITHUB=	yes
 GH_ACCOUNT=	gavinhoward
 
 HAS_CONFIGURE=	yes
 CONFIGURE_SCRIPT=	configure.sh
 CONFIGURE_ARGS=	-G
+CFLAGS+=	--std=c99
 
 CONFLICTS_INSTALL=	gnubc-[0-9]*
 
 do-install:
 		${INSTALL_PROGRAM} ${WRKSRC}/bin/bc ${STAGEDIR}${PREFIX}/bin/
 		${LN} ${STAGEDIR}${PREFIX}/bin/bc ${STAGEDIR}${PREFIX}/bin/dc
 		${INSTALL_MAN} ${WRKSRC}/manuals/bc.1 ${STAGEDIR}${MANPREFIX}/man/man1
 		${INSTALL_MAN} ${WRKSRC}/manuals/dc.1 ${STAGEDIR}${MANPREFIX}/man/man1
 		${WRKSRC}/locale_install.sh ${PREFIX}/share/nls/%L/%N.cat ${PORTNAME} ${STAGEDIR}
 		${INSTALL} -ls ${STAGEDIR}${PREFIX}/share/nls/en_US.US-ASCII/bc.cat ${STAGEDIR}${PREFIX}/share/nls/C/
 
 do-test:
 		${MAKE} -C ${WRKSRC} test
 
 .include <bsd.port.mk>