diff --git a/devel/stxxl/Makefile b/devel/stxxl/Makefile
index 27533dbbd9fc..cac5cc39fd32 100644
--- a/devel/stxxl/Makefile
+++ b/devel/stxxl/Makefile
@@ -1,25 +1,29 @@
 PORTNAME=	stxxl
 PORTVERSION=	1.4.1
+PORTREVISION=	1
 CATEGORIES=	devel
 MASTER_SITES=	SF
 
 MAINTAINER=	amdmi3@FreeBSD.org
 COMMENT=	Standard Template Library for Extra Large Data Sets
 WWW=		https://stxxl.org/ \
 		https://github.com/stxxl/stxxl
 
 LICENSE=	BSL
 LICENSE_FILE=	${WRKSRC}/LICENSE_1_0.txt
 
+DEPRECATED=	Abandoned upstream, does not build with CMake 4
+EXPIRATION_DATE=2026-11-30
+
 USES=		cmake
 CMAKE_OFF=	USE_GNU_PARALLEL  # may be enabled for future versions of clang with openmp support
 
 PORTDOCS=	*
 
 OPTIONS_DEFINE=	DOCS
 
 post-install-DOCS-on:
 	@${MKDIR} ${STAGEDIR}${DOCSDIR}
 	cd ${WRKSRC} && ${INSTALL_DATA} AUTHORS CHANGELOG README TODO ${STAGEDIR}${DOCSDIR}/
 
 .include <bsd.port.mk>