Index: head/devel/py-marshmallow/Makefile
===================================================================
--- head/devel/py-marshmallow/Makefile	(revision 501599)
+++ head/devel/py-marshmallow/Makefile	(revision 501600)
@@ -1,24 +1,24 @@
 # Created by: Mark Felder <feld@FreeBSD.org>
 # $FreeBSD$
 
 PORTNAME=	marshmallow
 DISTVERSION=	3.0.0rc5
 CATEGORIES=	devel python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	Simplified object serialization for Python
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}dateutil>=2.7.0:devel/py-dateutil@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}simplejson>=0:devel/py-simplejson@${PY_FLAVOR}
 
-USES=		python:3.5+
-USE_PYTHON=	autoplist distutils
+USES=		python
+USE_PYTHON=	autoplist concurrent distutils
 
 NO_ARCH=	yes
 
 .include <bsd.port.mk>