diff --git a/devel/qjson/Makefile b/devel/qjson/Makefile
index 60f4d1401fb5..b2c2aa354718 100644
--- a/devel/qjson/Makefile
+++ b/devel/qjson/Makefile
@@ -1,45 +1,47 @@
 PORTNAME=	qjson
 DISTVERSION=	0.9.0
 PORTREVISION=	7
 CATEGORIES=	devel
 PKGNAMESUFFIX=	-qt5
 
 MAINTAINER=	kde@FreeBSD.org
 COMMENT=	Library to manage JSON objects with Qt
 WWW=		http://qjson.sourceforge.net/
 
 LICENSE=	LGPL21
 LICENSE_FILE=	${WRKSRC}/COPYING.lib
 
 USES=		cmake compiler:c++11-lang pathfix qt:5
 USE_GITHUB=	yes
 GH_ACCOUNT=	flavio
 USE_LDCONFIG=	yes
 USE_QT=		core buildtools:build qmake:build
 CMAKE_OFF=	QT4_BUILD
 QT_SUFFIX=	-qt5
 
 _DOCSDIR=	${DOCSDIR}${QT_SUFFIX}
 DOCSDIR_REL=	${_DOCSDIR:S,^${PREFIX}/,,}
 PLIST_SUB+=	QT_SUFFIX="${QT_SUFFIX}" \
 		PORTVERSION="${PORTVERSION}"
 
 OPTIONS_DEFINE=	DOXYGEN
 OPTIONS_SUB=	yes
 
 DOXYGEN_BUILD_DEPENDS=	doxygen:devel/doxygen
 
-.include <bsd.port.options.mk>
-
-.if ${OPSYS} == FreeBSD && ${OSVERSION} >= 1400091
-CXXFLAGS+=  -Dregister=
-.endif
-
 post-build-DOXYGEN-on:
 	cd ${WRKSRC}/doc && doxygen
 
 post-install-DOXYGEN-on:
 	${MKDIR} ${STAGEDIR}${_DOCSDIR}
 	cd ${WRKSRC}/doc/html && ${COPYTREE_SHARE} . ${STAGEDIR}${_DOCSDIR}
 
-.include <bsd.port.mk>
+.include <bsd.port.pre.mk>
+
+# Clang 16 defaults to building in C++17, and throws an error when the
+# `register' keyword is used. Make clang just ignore the keyword instead.
+.if ${COMPILER_TYPE} == clang && ${COMPILER_VERSION} >= 160
+CXXFLAGS+=	-Wno-register
+.endif
+
+.include <bsd.port.post.mk>