diff --git a/biology/preseq/Makefile b/biology/preseq/Makefile
index f25bd80cbe9d..5a3de8a5ea2c 100644
--- a/biology/preseq/Makefile
+++ b/biology/preseq/Makefile
@@ -1,21 +1,24 @@
 PORTNAME=		preseq
 DISTVERSION=		3.2.0
 CATEGORIES=		biology
 # Github-generated distfiles are incomplete
 MASTER_SITES=		https://github.com/smithlabcode/preseq/releases/download/v${DISTVERSION}/
 
 MAINTAINER=	jwb@FreeBSD.org
 COMMENT=	Predict yield of distinct reads from a genomic library
 WWW=		https://github.com/smithlabcode/preseq
 
 LICENSE=	GPLv3
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
+NOT_FOR_ARCHS=		armv6 armv7 i386 mips powerpc powerpcspe
+NOT_FOR_ARCHS_REASON=	32-bit platforms are not useful for bioinformatics
+
 LIB_DEPENDS=	libhts.so:biology/htslib
 
 USES=		localbase
 
 GNU_CONFIGURE=	yes
 CONFIGURE_ARGS=	--enable-hts
 
 .include <bsd.port.mk>