Index: head/multimedia/libass/Makefile
===================================================================
--- head/multimedia/libass/Makefile	(revision 553425)
+++ head/multimedia/libass/Makefile	(revision 553426)
@@ -1,33 +1,33 @@
 # $FreeBSD$
 
 PORTNAME=	libass
 DISTVERSION=	0.15.0
 CATEGORIES=	multimedia devel
 MASTER_SITES=	https://github.com/${PORTNAME}/${PORTNAME}/releases/download/${DISTVERSION}/
 
 MAINTAINER=	multimedia@FreeBSD.org
 COMMENT=	Portable ASS/SSA subtitle renderer
 
 LICENSE=	ISCL
 LICENSE_FILE=	${WRKSRC}/COPYING
 
 LIB_DEPENDS=	libfreetype.so:print/freetype2 \
 		libharfbuzz.so:print/harfbuzz \
 		libfribidi.so:converters/fribidi \
 		libfontconfig.so:x11-fonts/fontconfig
 
-USES=		autoreconf iconv libtool pathfix pkgconfig tar:xz
+USES=		autoreconf compiler:c11 iconv libtool pathfix pkgconfig tar:xz
 GNU_CONFIGURE=	yes
 USE_LDCONFIG=	yes
 INSTALL_TARGET=	install-strip
 LDFLAGS_i386=	-Wl,-znotext
 
 OPTIONS_DEFINE_amd64=	ASM
 OPTIONS_DEFINE_i386=	ASM
 OPTIONS_DEFAULT_amd64=	ASM
 OPTIONS_DEFAULT_i386=	ASM
 
 ASM_BUILD_DEPENDS=nasm:devel/nasm
 ASM_CONFIGURE_ENABLE=asm
 
 .include <bsd.port.mk>