diff --git a/japanese/Wnn7-lib/Makefile b/japanese/Wnn7-lib/Makefile
index 0214fa30a5f4..807d9a29d55e 100644
--- a/japanese/Wnn7-lib/Makefile
+++ b/japanese/Wnn7-lib/Makefile
@@ -1,37 +1,46 @@
 PORTNAME=	Wnn7
 PORTVERSION=	2001.10.17
 PORTREVISION=	3
 CATEGORIES=	japanese
 MASTER_SITES=	http://www.omronsoft.co.jp/SP/pcunix/sdk/wnn/
 PKGNAMESUFFIX=	-lib
 DISTNAME=	Wnn7SDK
 
 MAINTAINER=	hrs@FreeBSD.org
 COMMENT=	Wnn7 client library
 WWW=		https://www.omronsoft.co.jp/
 
 USES=		imake tar:tgz
 USE_LDCONFIG=	yes
 WRKSRC=		${WRKDIR}/src
 PORTDOCS=	README
 
 OPTIONS_DEFINE=	DOCS
 
+.include <bsd.port.options.mk>
+
+.if ${OPSYS} == FreeBSD && ( ${OSVERSION} >= 1400091 || ( ${OSVERSION} >= 1302507 && ${OSVERSION} < 1400000 ))
+USES+=	llvm:max=14
+CC=	clang${LLVM_VERSION}
+CPP=	clang-cpp${LLVM_VERSION}
+CXX=	clang++${LLVM_VERSION}
+.endif
+
 post-patch:
 	@${REINPLACE_CMD} -e 's,/usr/X11R6,${LOCALBASE},g' \
 		${WRKSRC}/config/Project.tmpl \
 		${WRKSRC}/config/X11.tmpl \
 		${WRKSRC}/Makefile.ini
 	@${REINPLACE_CMD} -e 's/((/(/' ${WRKSRC}/config/X11.tmpl
 
 # Warning: we cannot use USE_IMAKE.
 do-build:
 	(cd ${WRKSRC} && ${SETENV} ${MAKE_ENV} make World -f Makefile.ini)
 
 post-install:
 	${MKDIR} ${STAGEDIR}${PREFIX}/include/wnn7/wnn
 	${INSTALL_DATA} ${WRKSRC}/Wnn/include/*.h ${STAGEDIR}${PREFIX}/include/wnn7/wnn
 	${MKDIR} ${STAGEDIR}${DOCSDIR}
 	(cd ${WRKSRC} && ${INSTALL_DATA} ${PORTDOCS} ${STAGEDIR}${DOCSDIR})
 
 .include <bsd.port.mk>