Index: head/textproc/cmark/Makefile
===================================================================
--- head/textproc/cmark/Makefile	(revision 472897)
+++ head/textproc/cmark/Makefile	(revision 472898)
@@ -1,23 +1,25 @@
 # Created by: Tobias Kortkamp <t@tobik.me>
 # $FreeBSD$
 
 PORTNAME=	cmark
 PORTVERSION=	0.28.3
 CATEGORIES=	textproc
 
 MAINTAINER=	tobik@FreeBSD.org
 COMMENT=	CommonMark parsing and rendering library and program in C
 
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/COPYING
 
+CONFLICTS_INSTALL=	py[2-3][0-9]-CommonMark
+
 USES=		cmake:outsource python:3.4+,test
 USE_GITHUB=	yes
 GH_ACCOUNT=	commonmark
 USE_LDCONFIG=	yes
 
 CMAKE_ARGS=	-DCMAKE_INSTALL_LIBDIR:STRING="lib"
 PLIST_SUB=	VERSION=${PORTVERSION}
 TEST_TARGET=	test
 
 .include <bsd.port.mk>
Index: head/textproc/py-CommonMark/Makefile
===================================================================
--- head/textproc/py-CommonMark/Makefile	(revision 472897)
+++ head/textproc/py-CommonMark/Makefile	(revision 472898)
@@ -1,22 +1,24 @@
 # $FreeBSD$
 
 PORTNAME=	CommonMark
 PORTVERSION=	0.7.5
 PORTREVISION=	2
 CATEGORIES=	textproc python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	romain@FreeBSD.org
 COMMENT=	Python parser for the CommonMark Markdown spec
 
 LICENSE=	BSD3CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
+CONFLICTS_INSTALL=	cmark
+
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}future>0:devel/py-future@${PY_FLAVOR}
 
 USES=		python
 USE_PYTHON=	autoplist concurrent distutils
 NO_ARCH=	yes
 
 .include <bsd.port.mk>