Index: head/science/py-ase/Makefile
===================================================================
--- head/science/py-ase/Makefile	(revision 507520)
+++ head/science/py-ase/Makefile	(revision 507521)
@@ -1,27 +1,27 @@
 # $FreeBSD$
 
 PORTNAME=	ase
 DISTVERSION=	3.18.0
 PORTREVISION=	1
 CATEGORIES=	science python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Atomic simulation environment
 
 LICENSE=	LGPL21
 LICENSE_FILE=	${WRKSRC}/COPYING.LESSER
 
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}Flask>0:www/py-flask@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}matplotlib>0:math/py-matplotlib@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scipy>0:science/py-scipy@${PY_FLAVOR} \
 		${PYNUMPY} \
 		nwchem:science/nwchem
 
-USES=		python
+USES=		python:3.5+
 USE_PYTHON=	distutils concurrent autoplist
 
 NO_ARCH=	yes
 
 .include <bsd.port.mk>