Index: head/devel/py-protobuf/Makefile
===================================================================
--- head/devel/py-protobuf/Makefile	(revision 453770)
+++ head/devel/py-protobuf/Makefile	(revision 453771)
@@ -1,33 +1,33 @@
 # Created by: vanilla@
 # $FreeBSD$
 
 PORTNAME=	protobuf
 PORTVERSION=	3.4.1
 DISTVERSIONPREFIX=	v
 CATEGORIES=	devel python
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	Google protobuf Python Client Library
 
 LICENSE=	BSD3CLAUSE
 LICENSE_FILE=	${WRKSRC}/../LICENSE
 
 BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}six>=1.9:devel/py-six \
 		protoc:devel/protobuf
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}six>=1.9:devel/py-six
 
 DO_MAKE_TEST=	${PYTHON_CMD} ${PYDISTUTILS_SETUP}
 NO_ARCH=	yes
 TEST_TARGET=	test
 USE_PYTHON=	autoplist distutils
-USES=		python
+USES?=		python
 WRKSRC_SUBDIR=	python
 
 GH_ACCOUNT=	google
 USE_GITHUB=	yes
 
 post-patch:
 	@${MKDIR} ${WRKSRC}/google/protobuf/compiler/
 
 .include <bsd.port.mk>