diff --git a/cad/nvc/Makefile b/cad/nvc/Makefile
index ef004c944c10..f998b02499f8 100644
--- a/cad/nvc/Makefile
+++ b/cad/nvc/Makefile
@@ -1,42 +1,45 @@
 PORTNAME=	nvc
 DISTVERSIONPREFIX=	r
 DISTVERSION=	1.6.2
 CATEGORIES=	cad
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	VHDL compiler and simulator
 
 LICENSE=	GPLv3
 LICENSE_FILE=	${WRKSRC}/COPYING
 
+BROKEN_armv6=	use of undeclared identifier '_URC_NO_REASON', see https://github.com/nickg/nvc/issues/492
+BROKEN_armv7=	use of undeclared identifier '_URC_NO_REASON', see https://github.com/nickg/nvc/issues/492
+
 BUILD_DEPENDS=	llvm-config${LLVM_VERSION}:devel/llvm${LLVM_VERSION}
 RUN_DEPENDS=	llvm${LLVM_VERSION}>0:devel/llvm${LLVM_VERSION}
 TEST_DEPENDS=	check>0:devel/check
 
 USES=		autoreconf compiler:c++14-lang localbase pkgconfig
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	nickg
 
 GNU_CONFIGURE=	yes
 
 LDFLAGS+=	-lexecinfo
 
 CONFIGURE_ARGS=	--with-llvm=${LOCALBASE}/bin/llvm-config${LLVM_VERSION}
 
 TEST_TARGET=	check # one test fails
 
 MAKE_ARGS=	CFLAGS="${CFLAGS}" # only for tests
 
 LLVM_VERSION=	${LLVM_DEFAULT}
 
 .include <bsd.port.options.mk>
 
 .if ${OPSYS} == FreeBSD && ${OSVERSION} < 1400052 # devel/libunwind installs include/unwind.h only before that version, after which it probably exists in the base
 BUILD_DEPENDS+=	${LOCALBASE}/include/unwind.h:devel/libunwind
 .endif
 
 post-install:
 	${FIND} ${STAGEDIR}${PREFIX} -name "*.so" | ${XARGS} ${STRIP_CMD}
 
 .include <bsd.port.mk>