Index: head/devel/tlx/Makefile
===================================================================
--- head/devel/tlx/Makefile	(revision 557868)
+++ head/devel/tlx/Makefile	(revision 557869)
@@ -1,20 +1,20 @@
 # $FreeBSD$
 
 PORTNAME=	tlx
 DISTVERSION=	v0.5.20200222-5
 DISTVERSIONSUFFIX=	-g8982a9d
 CATEGORIES=	devel
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Collection of C++ data structures, algorithms, miscellaneous helpers
 
 LICENSE=	BSL
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
-USES=		cmake
+USES=		cmake compiler:c++17-lang
 USE_GITHUB=	yes
 USE_LDCONFIG=	yes
 
 CMAKE_ON=	TLX_BUILD_SHARED_LIBS
 
 .include <bsd.port.mk>