Index: head/math/py-bayesian-optimization/Makefile
===================================================================
--- head/math/py-bayesian-optimization/Makefile	(revision 520329)
+++ head/math/py-bayesian-optimization/Makefile	(revision 520330)
@@ -1,25 +1,25 @@
 # Created by: Po-Chuan Hsieh <sunpoet@FreeBSD.org>
 # $FreeBSD$
 
 PORTNAME=	bayesian-optimization
 PORTVERSION=	1.0.1
 PORTREVISION=	1
 CATEGORIES=	math python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	Bayesian Optimization package
 
 LICENSE=	MIT
 
 RUN_DEPENDS=	${PYNUMPY} \
 		${PYTHON_PKGNAMEPREFIX}scikit-learn>=0.18.0:science/py-scikit-learn@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scipy>=0.14.0:science/py-scipy@${PY_FLAVOR}
 
-USES=		python
+USES=		python:3.5+
 USE_PYTHON=	autoplist concurrent distutils
 
 NO_ARCH=	yes
 
 .include <bsd.port.mk>
Index: head/multimedia/subsync/Makefile
===================================================================
--- head/multimedia/subsync/Makefile	(revision 520329)
+++ head/multimedia/subsync/Makefile	(revision 520330)
@@ -1,31 +1,31 @@
 # $FreeBSD$
 
 PORTNAME=	subsync
 DISTVERSION=	g20190702
 CATEGORIES=	multimedia python
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Synchronize your subtitles using machine learning
 
 LICENSE=	APACHE20
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	${PYNUMPY} \
 		${PYTHON_PKGNAMEPREFIX}argparse>0:devel/py-argparse@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}ffmpeg-python>0:multimedia/py-ffmpeg-python@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}future>0:devel/py-future@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}pysrt>0:textproc/py-pysrt@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scikit-learn>0:science/py-scikit-learn@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}six>0:devel/py-six@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}tqdm>0:misc/py-tqdm@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}webrtcvad>0:audio/py-webrtcvad@${PY_FLAVOR}
 
-USES=		python
+USES=		python:3.5+
 USE_GITHUB=	yes
 GH_ACCOUNT=	smacke # tympanix account has another version of the same project requiring tensorflow
 GH_TAGNAME=	d9798a5
 USE_PYTHON=	distutils concurrent noflavors autoplist
 
 NO_ARCH=	yes
 
 .include <bsd.port.mk>
Index: head/science/py-chainer-chemistry/Makefile
===================================================================
--- head/science/py-chainer-chemistry/Makefile	(revision 520329)
+++ head/science/py-chainer-chemistry/Makefile	(revision 520330)
@@ -1,28 +1,28 @@
 # $FreeBSD$
 
 PORTNAME=	chainer-chemistry
 DISTVERSION=	0.6.0
 CATEGORIES=	science biology
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Library for deep learning in biology and chemistry
 
 LICENSE=	MIT
 
 RUN_DEPENDS=	${PYNUMPY} \
 		${PYTHON_PKGNAMEPREFIX}chainer>0:science/py-chainer@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}joblib>0:devel/py-joblib@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}matplotlib>0:math/py-matplotlib@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}pandas>0:math/py-pandas@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scipy>0:science/py-scipy@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scikit-learn>0:science/py-scikit-learn@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}tqdm>0:misc/py-tqdm@${PY_FLAVOR}
 
-USES=		python
+USES=		python:3.5+
 USE_PYTHON=	distutils autoplist
 
 NO_ARCH=	yes
 
 .include <bsd.port.mk>
Index: head/science/py-oddt/Makefile
===================================================================
--- head/science/py-oddt/Makefile	(revision 520329)
+++ head/science/py-oddt/Makefile	(revision 520330)
@@ -1,29 +1,29 @@
 # $FreeBSD$
 
 PORTNAME=	oddt
 DISTVERSION=	0.6
 PORTREVISION=	2
 CATEGORIES=	science python
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Open Drug Discovery Toolkit
 
 LICENSE=	BSD3CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	${PYNUMPY} \
 		${PYTHON_PKGNAMEPREFIX}joblib>0:devel/py-joblib@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}pandas>0:math/py-pandas@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scikit-learn>0:science/py-scikit-learn@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scipy>=0.9.0:science/py-scipy@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}six>0:devel/py-six@${PY_FLAVOR}
 RUN_DEPENDS:=	${BUILD_DEPENDS}
 
-USES=		python
+USES=		python:3.5+
 USE_GITHUB=	yes
 USE_PYTHON=	distutils concurrent autoplist
 
 NO_ARCH=	yes
 
 .include <bsd.port.mk>