diff --git a/www/libdatachannel/Makefile b/www/libdatachannel/Makefile
index d9987fbbef57..df5ddf8acb81 100644
--- a/www/libdatachannel/Makefile
+++ b/www/libdatachannel/Makefile
@@ -1,34 +1,41 @@
 PORTNAME=	libdatachannel
 DISTVERSIONPREFIX=	v
 DISTVERSION=	0.18.2
 CATEGORIES=	www
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	WebRTC Data Channels, WebRTC Media Transport, and WebSockets library
 WWW=		https://github.com/paullouisageneau/libdatachannel
 
 LICENSE=	LGPL21
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 LIB_DEPENDS=	libsrtp2.so:net/libsrtp2
 
 USES=		cmake compiler:c++17-lang ssl
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	paullouisageneau
 GH_TUPLE=	SergiusTheBest:plog:d8461e9d473e59fbcc1f79eee021550dcf81e618:SergiusTheBest_plog/deps/plog \
 		sctplab:usrsctp:7c31bd35c79ba67084ce029511193a19ceb97447:sctplab_usrsctp/deps/usrsctp \
 		paullouisageneau:libjuice:0dabc046cd23da6908749e4c6add834ec29a7c49:paullouisageneau_libjuice/deps/libjuice \
 		nlohmann:json:4f8fba14066156b73f1189a2b8bd568bde5284c5:nlohmann_json/deps/json \
 		cisco:libsrtp:a566a9cfcd619e8327784aa7cff4a1276dc1e895:cisco_libsrtp/deps/libsrtp
 
 CMAKE_ON=	USE_SYSTEM_SRTP NO_EXAMPLES NO_TESTS
 
+.include <bsd.port.pre.mk>
+
+.if ${OPSYS} == FreeBSD && ${OSVERSION} >= 1400079
+CFLAGS+=       -Wno-error=unused-but-set-variable \
+			   -Wno-error=strict-prototypes
+.endif
+
 do-test: # tests require dual stack to be enabled with 'sysctl net.inet6.ip6.v6only=0', at least one test is known to fail
 	# tests fail (intermittently?): https://github.com/paullouisageneau/libdatachannel/issues/682
 	@cd ${BUILD_WRKSRC} && \
 		${SETENV} ${CONFIGURE_ENV} ${CMAKE_BIN} ${CMAKE_ARGS} -DNO_TESTS:BOOL=OFF ${CMAKE_SOURCE_PATH} && \
 		${SETENV} ${MAKE_ENV} ${MAKE_CMD} ${MAKE_ARGS} ${ALL_TARGET} && \
 		./tests-${DISTVERSION:C/-.*//}
 
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>