Index: head/devel/py-pyvisa-py/Makefile
===================================================================
--- head/devel/py-pyvisa-py/Makefile	(revision 549398)
+++ head/devel/py-pyvisa-py/Makefile	(revision 549399)
@@ -1,38 +1,38 @@
 # $FreeBSD$
 
 PORTNAME=	pyvisa-py
 PORTVERSION=	0.5.0
 CATEGORIES=	devel python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 DISTNAME=	PyVISA-py-${PORTVERSION}
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	PyVISA backend in pure Python
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}setuptools_scm>=3.4.3:devel/py-setuptools_scm@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}wheel>=0:devel/py-wheel@${PY_FLAVOR}
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}typing-extensions>=0:devel/py-typing-extensions@${PY_FLAVOR}
 
-USES=		python
+USES=		python:3.6+
 USE_PYTHON=	autoplist concurrent distutils
 
 NO_ARCH=	yes
 
 OPTIONS_DEFINE=	SERIAL USB
 SERIAL_DESC=	Access to devices via RS-232
 USB_DESC=	Access to devices via USB
 
 SERIAL_RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pyserial>=3.0:comms/py-pyserial@${PY_FLAVOR}
 USB_RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pyusb>=0:devel/py-pyusb@${PY_FLAVOR}
 
 .include <bsd.port.pre.mk>
 
 .if ${PYTHON_REL} < 3800
 RUN_DEPENDS+=	${PYTHON_PKGNAMEPREFIX}importlib-metadata>=0:devel/py-importlib-metadata@${PY_FLAVOR}
 .endif
 
 .include <bsd.port.post.mk>