Index: head/lang/ponyc/Makefile
===================================================================
--- head/lang/ponyc/Makefile	(revision 473528)
+++ head/lang/ponyc/Makefile	(revision 473529)
@@ -1,48 +1,48 @@
 # $FreeBSD$
 
 PORTNAME=	ponyc
 DISTVERSION=	0.23.0
 CATEGORIES=	lang
 
 MAINTAINER=	greg@unrelenting.technology
 COMMENT=	Pony language compiler
 
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
-ONLY_FOR_ARCHS=		amd64
+ONLY_FOR_ARCHS=		aarch64 amd64
 ONLY_FOR_ARCHS_REASON=	Undefined reference to __atomic_compare_exchange_8
 BROKEN_FreeBSD_10=	Undefined reference to __atomic_compare_exchange
 
 LIB_DEPENDS=	libunwind.so:devel/libunwind
 BUILD_DEPENDS=	llvm-link${LLVM_VERSION}:devel/llvm${LLVM_VERSION}
 RUN_DEPENDS=	llvm-link${LLVM_VERSION}:devel/llvm${LLVM_VERSION}
 
 OPTIONS_DEFINE=	DOCS EXAMPLES
 
 USES=		gmake ncurses compiler:c++11-lang
 MAKE_ARGS=	config=release
 
 LLVM_VERSION=	50
 
 PLIST_SUB=	VERSION="${DISTVERSION}"
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	ponylang
 
 PORTDOCS=	*.md
 
-MAKE_ENV=	prefix=${PREFIX} verbose=true
+MAKE_ENV=	prefix=${PREFIX} verbose=true ${"${ARCH}" == aarch64:?arch=armv8-a:}
 
 post-install:
 	${STRIP_CMD} ${STAGEDIR}${PREFIX}/lib/pony/${DISTVERSION}/bin/ponyc
 
 post-install-DOCS-on:
 	${MKDIR} ${STAGEDIR}${DOCSDIR}
 	${INSTALL_DATA} ${WRKSRC}/*.md ${STAGEDIR}${DOCSDIR}
 
 post-install-EXAMPLES-on:
 	${MKDIR} ${STAGEDIR}${EXAMPLESDIR}
 	@(cd ${WRKSRC}/examples && ${COPYTREE_SHARE} . ${STAGEDIR}${EXAMPLESDIR})
 
 .include <bsd.port.mk>