diff --git a/audio/xanalyser/Makefile b/audio/xanalyser/Makefile
index 4f0c2e0fe1a9..1b3be9279f99 100644
--- a/audio/xanalyser/Makefile
+++ b/audio/xanalyser/Makefile
@@ -1,27 +1,29 @@
 PORTNAME=	xanalyser
 PORTVERSION=	1.32
 PORTREVISION=	3
 CATEGORIES=	audio hamradio
 MASTER_SITES=	http://arvin.schnell-web.net/xanalyser/ \
 		LOCAL/db
 
 MAINTAINER=	hamradio@FreeBSD.org
 COMMENT=	Spectrum analyser
 WWW=		http://arvin.schnell-web.net/xanalyser/
 
 LICENSE=	GPLv2+
 LICENSE_FILE=	${WRKSRC}/COPYING
 
 USES=		gmake libtool motif tar:bzip2 xorg
 USE_XORG=	x11 xmu ice sm xt xext
+USE_CXXSTD=	c++14 # to fix build on 14 with clang-16 that has c++20 by default: error: ISO C++17 does not allow 'register' storage class specifier
+
 GNU_CONFIGURE=	yes
 
 PLIST_FILES=	bin/xanalyser lib/X11/app-defaults/XAnalyser man/man1/xanalyser.1.gz
 
 post-patch:
 	@${REINPLACE_CMD} -e 's|%%LOCALBASE%%|${LOCALBASE}|g' \
 	    -e 's|%%MOTIFLIB%%|${MOTIFLIB} |g' \
 	    -e 's|%%PREFIX%%|${PREFIX}|g' \
 	    ${WRKSRC}/xanalyser.spec.in ${WRKSRC}/src/Makefile.in
 
 .include <bsd.port.mk>