diff --git a/net-mgmt/irrtoolset/Makefile b/net-mgmt/irrtoolset/Makefile
index 0cbce42f76cf..ef787e63c27b 100644
--- a/net-mgmt/irrtoolset/Makefile
+++ b/net-mgmt/irrtoolset/Makefile
@@ -1,25 +1,31 @@
 PORTNAME=	irrtoolset
 DISTVERSIONPREFIX=	release-
 DISTVERSION=	5.1.3
 PORTREVISION=	1
 CATEGORIES=	net-mgmt
 
 MAINTAINER=	rkoberman@gmail.com
 COMMENT=	Suite of routing policy tools to interact with the IRR
 WWW=		https://github.com/irrtoolset/irrtoolset
 
 LICENSE=	MIT GPLv2+ RIPE_NCC
 LICENSE_COMB=	multi
 LICENSE_NAME_RIPE_NCC=	RIPE NCC license
 LICENSE_FILE=	${WRKSRC}/COPYING
 LICENSE_PERMS_RIPE_NCC=	dist-mirror dist-sell pkg-mirror pkg-sell auto-accept
 
 USES=		autoreconf bison gmake libtool
 GNU_CONFIGURE=	yes
 USE_GITHUB=	yes
 
 PLIST_FILES=	bin/rpslcheck bin/peval bin/rtconfig \
 		man/man1/rtconfig.1.gz man/man1/peval.1.gz \
 		man/man1/rpslcheck.1.gz man/man1/irrtoolset-errors.1.gz
 
+.include <bsd.port.options.mk>
+
+.if ${OPSYS} == FreeBSD && ( ${OSVERSION} >= 1400091 || ( ${OSVERSION} >= 1302507 && ${OSVERSION} < 1400000 ))
+CFLAGS+=  -Dregister=
+.endif
+
 .include <bsd.port.mk>