Index: head/www/varnish-libvmod-dynamic/Makefile
===================================================================
--- head/www/varnish-libvmod-dynamic/Makefile	(revision 554037)
+++ head/www/varnish-libvmod-dynamic/Makefile	(revision 554038)
@@ -1,38 +1,39 @@
 # $FreeBSD$
 
 PORTNAME=	libvmod-dynamic
 PORTVERSION=	20201026
 CATEGORIES=	www
 PKGNAMEPREFIX=	varnish-
 
 MAINTAINER=	zi@FreeBSD.org
 COMMENT=	Varnish Module (vmod) for dynamic backends
 
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 LIB_DEPENDS=	libgetdns.so:dns/getdns
 BUILD_DEPENDS=	rst2man:textproc/py-docutils@${PY_FLAVOR}
 
-USES=		autoreconf gmake libtool pkgconfig python:3.5+,build varnish:6
+USES=		autoreconf compiler:c11 gmake libtool pkgconfig \
+		python:3.5+,build varnish:6
 USE_LDCONFIG=	yes
 
 GNU_CONFIGURE=	yes
 CONFIGURE_ARGS=	--disable-static
 INSTALL_TARGET=	install-strip
 DOCSDIR=	${PREFIX}/share/doc/vmod-dynamic
 MAKE_JOBS_UNSAFE=	yes
 
 CFLAGS+=	-I${WRKSRC}/src
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	nigoroll
 GH_TAGNAME=	7a699ef
 
 OPTIONS_DEFINE=	DOCS
 
 post-patch:
 	${REINPLACE_CMD} 's|$${VARNISHAPI_DATAROOTDIR}|${LOCALBASE}/share|' \
 		${WRKSRC}/Makefile.am
 
 .include <bsd.port.mk>