Index: head/devel/libthmap/Makefile
===================================================================
--- head/devel/libthmap/Makefile	(revision 503922)
+++ head/devel/libthmap/Makefile	(revision 503923)
@@ -1,26 +1,26 @@
 # $FreeBSD$
 
 PORTNAME=	libthmap
 PORTVERSION=	g2019052401
 CATEGORIES=	devel
 
 MAINTAINER=	swills@FreeBSD.org
 COMMENT=	Concurrent trie-hash map library
 
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/../LICENSE
 
-USES=		gmake libtool:build
+USES=		compiler:c11 gmake libtool:build
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	rmind
 GH_PROJECT=	thmap
 GH_TAGNAME=	0f1cbfc
 WRKSRC_SUBDIR=	src
 USE_LDCONFIG=	yes
 MAKE_ENV=	DESTDIR=${STAGEDIR}${PREFIX} \
 		INCDIR=${LOCALBASE}/include \
 		LIBDIR=${LOCALBASE}/lib \
 		MANDIR=${LOCALBASE}/man
 
 .include <bsd.port.mk>