Index: head/devel/stlink/Makefile
===================================================================
--- head/devel/stlink/Makefile	(revision 539376)
+++ head/devel/stlink/Makefile	(revision 539377)
@@ -1,41 +1,42 @@
 # $FreeBSD$
 
 PORTNAME=	stlink
 PORTVERSION=	1.6.1
 DISTVERSIONPREFIX=	v
 #PORTREVISION=	0
 CATEGORIES=	devel
 
 MAINTAINER=	lev@FreeBSD.org
 COMMENT=	STM32 ST-Link JTAG variant tools
 
 LICENSE=	BSD3CLAUSE
 
 OPTIONS_DEFINE=		GTK3 DOCS
 OPTIONS_SUB=		yes
 GTK3_EXTRA_PATCHES_OFF=	${FILESDIR}/extra-pacth-turn-off-gtk
 GTK3_USES=		gnome
 GTK3_USE=		GNOME=gtk30
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	texane
 
 USES=		cmake pkgconfig
+USE_CSTD=	c99
 USE_LDCONFIG=	yes
 
 PORTDOCS=	README.md ${ALLDOCS}
 
 ALLDOCS=	compiling.md developer.txt devices_boards.md \
 		flashloaders.md release.md tutorial.md \
 		version_support.md
 
 .include <bsd.port.pre.mk>
 
 post-install:
 	${MKDIR} ${STAGEDIR}${DOCSDIR}
 	${INSTALL_DATA} ${WRKSRC}/README.md ${STAGEDIR}${DOCSDIR}/README.md
 .for DOC in ${ALLDOCS}
 	${INSTALL_DATA} ${WRKSRC}/doc/${DOC} ${STAGEDIR}${DOCSDIR}/${DOC}
 .endfor
 
 .include <bsd.port.post.mk>