Index: head/astro/py-astropy/Makefile
===================================================================
--- head/astro/py-astropy/Makefile	(revision 520326)
+++ head/astro/py-astropy/Makefile	(revision 520327)
@@ -1,23 +1,23 @@
 # Created by: nwhitehorn
 # $FreeBSD$
 
 PORTNAME=	astropy
 DISTVERSION=	3.1.2
 PORTEPOCH=	2
 CATEGORIES=	astro
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	nwhitehorn@FreeBSD.org
 COMMENT=	Community-developed python astronomy tools
 
 LICENSE=	BSD3CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE.rst
 
 BUILD_DEPENDS=	${PYNUMPY}
 RUN_DEPENDS=	${PYNUMPY}
 
-USES=		python:3.5+
+USES=		compiler:c11 python:3.5+
 USE_PYTHON=	autoplist distutils
 
 .include <bsd.port.mk>