Index: head/converters/hs-dataenc/Makefile
===================================================================
--- head/converters/hs-dataenc/Makefile	(revision 457240)
+++ head/converters/hs-dataenc/Makefile	(revision 457241)
@@ -1,14 +1,16 @@
 # $FreeBSD$
 
 PORTNAME=	dataenc
 PORTVERSION=	0.14.0.7
 PORTREVISION=	3
 CATEGORIES=	converters haskell
 
 MAINTAINER=	haskell@FreeBSD.org
 COMMENT=	Data encoding library
 
 LICENSE=	BSD3CLAUSE
 
+CONFLICTS_INSTALL=	hs-sandi-[0-9]*
+
 .include "${.CURDIR}/../../lang/ghc/bsd.cabal.mk"
 .include <bsd.port.mk>
Index: head/converters/hs-sandi/Makefile
===================================================================
--- head/converters/hs-sandi/Makefile	(revision 457240)
+++ head/converters/hs-sandi/Makefile	(revision 457241)
@@ -1,15 +1,17 @@
 # $FreeBSD$
 
 PORTNAME=	sandi
 PORTVERSION=	0.4.0
 CATEGORIES=	converters haskell
 
 MAINTAINER=	haskell@FreeBSD.org
 COMMENT=	Data encoding library
 
 LICENSE=	BSD3CLAUSE
 
+CONFLICTS_INSTALL=	hs-dataenc-[0-9]*
+
 USE_CABAL=	conduit exceptions stringsearch
 
 .include "${.CURDIR}/../../lang/ghc/bsd.cabal.mk"
 .include <bsd.port.mk>