Index: head/graphics/glx-utils/Makefile
===================================================================
--- head/graphics/glx-utils/Makefile	(revision 548259)
+++ head/graphics/glx-utils/Makefile	(revision 548260)
@@ -1,36 +1,37 @@
 # $FreeBSD$
 
 PORTNAME=	glx-utils
 DISTVERSIONPREFIX=	${GL_ACCOUNT}-${GL_PROJECT}-
 DISTVERSION=	8.4.0-43
 CATEGORIES=	graphics
 
 MAINTAINER=	jbeich@FreeBSD.org
 COMMENT=	List GLX capabilities and simple renderer
 
 LICENSE=	MIT
 
 CONFLICTS_INSTALL=	mesa-demos
 
 USES=		gl localbase:ldflags xorg
+USE_CSTD=	c99
 USE_GITLAB=	yes
 USE_GL=		gl
 USE_XORG=	x11
 GL_SITE=	https://gitlab.freedesktop.org
 GL_ACCOUNT=	mesa
 GL_PROJECT=	demos
 GL_COMMIT=	0de7436be906b720f503668609404c97ea3a124b
 WRKSRC_SUBDIR=	src/xdemos
 PLIST_FILES=	bin/glxgears \
 		bin/glxinfo \
 		${NULL}
 
 do-build:
 	(cd ${WRKSRC} && ${CC} ${CFLAGS} -o glxinfo glxinfo.c glinfo_common.c ${LDFLAGS} -lGL -lX11)
 	(cd ${WRKSRC} && ${CC} ${CFLAGS} -o glxgears glxgears.c ${LDFLAGS} -lGL -lX11 -lm)
 
 do-install:
 	${INSTALL_PROGRAM} ${PLIST_FILES:Mbin/*:S,^bin,${WRKSRC},} \
 		${STAGEDIR}${PREFIX}/bin
 
 .include <bsd.port.mk>