diff --git a/x11-toolkits/ztoolkit/Makefile b/x11-toolkits/ztoolkit/Makefile
index 768b0e004ab6..ac55ff3fad26 100644
--- a/x11-toolkits/ztoolkit/Makefile
+++ b/x11-toolkits/ztoolkit/Makefile
@@ -1,20 +1,20 @@
 PORTNAME=	ztoolkit
 DISTVERSION=	0.1.2
 CATEGORIES=	x11-toolkits
 MASTER_SITES=	https://git.zrythm.org/zrythm/ztoolkit/archive/ # .../v${DISTVERSION}.tar.gz&dummy=/ doesn't work with Gitea
 DISTNAME=	v${DISTVERSION}
 DIST_SUBDIR=	${PORTNAME}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	GUI toolkit heavily inspired by GTK
 
 LICENSE=	AGPLv3
 LICENSE_FILE=	${WRKSRC}/COPYING
 
-USES=		gnome meson pkgconfig xorg
+USES=		compiler:c11 gnome meson pkgconfig xorg
 USE_GNOME=	cairo
 USE_XORG=	x11
 
 WRKSRC=		${WRKDIR}/${PORTNAME}
 
 .include <bsd.port.mk>