diff --git a/biology/preseq/Makefile b/biology/preseq/Makefile
index f25bd80cbe9d..5a3de8a5ea2c 100644
--- a/biology/preseq/Makefile
+++ b/biology/preseq/Makefile
@@ -11,6 +11,9 @@ 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