diff --git a/textproc/add-css-links/Makefile b/textproc/add-css-links/Makefile
index 358f685d9af2..96b381fe656a 100644
--- a/textproc/add-css-links/Makefile
+++ b/textproc/add-css-links/Makefile
@@ -1,20 +1,23 @@
 PORTNAME=	add-css-links
 PORTVERSION=	1.0
 PORTREVISION=	1
 CATEGORIES=	textproc
 MASTER_SITES=	http://aaronland.info/xsl/xhtml/add-css-links/
 
 MAINTAINER=	ports@FreeBSD.org
 COMMENT=	Add one or more CSS <link> elements to an XHTML document
 WWW=		https://aaronland.info/xsl/xhtml/add-css-links
 
+DEPRECATED=	Obsolete and unmaintained in tree for years
+EXPIRATION_DATE=2025-04-30
+
 NO_BUILD=	yes
 WRKSRC=		${WRKDIR}/xhtml
 
 PLIST_FILES=	share/xsl/xhtml/add-css-links.xsl
 
 do-install:
 	@${MKDIR} ${STAGEDIR}${PREFIX}/share/xsl/xhtml
 	${CP} ${WRKSRC}/*.xsl ${STAGEDIR}${PREFIX}/share/xsl/xhtml/
 
 .include <bsd.port.mk>