diff --git a/security/sshguard/Makefile b/security/sshguard/Makefile
index ba84072408b4..48621f158097 100644
--- a/security/sshguard/Makefile
+++ b/security/sshguard/Makefile
@@ -1,30 +1,31 @@
 # Created by: Mij <mij@bitchx.it>
 
 PORTNAME=	sshguard
 PORTVERSION=	2.4.2
+PORTREVISION=	1
 PORTEPOCH=	1
 CATEGORIES=	security
 MASTER_SITES=	SF/sshguard/sshguard/${PORTVERSION}
 
 MAINTAINER=	kevinz5000@gmail.com
 COMMENT=	Protect hosts from brute-force attacks against SSH and other services
 
 LICENSE=	BSD2CLAUSE
 
 USE_RC_SUBR=	sshguard
 
 GNU_CONFIGURE=	yes
 SUB_FILES=	pkg-message
 
 post-patch:
 	@${REINPLACE_CMD} -e 's|%PREFIX%|${PREFIX}|' \
 		${WRKSRC}/doc/sshguard.8.rst
 	@${REINPLACE_CMD} -e 's|/usr/local|${PREFIX}|' \
 		${WRKSRC}/examples/sshguard.conf.sample
 
 post-install:
 	${MKDIR} ${STAGEDIR}${PREFIX}/etc
 	${INSTALL_DATA} ${WRKSRC}/examples/sshguard.conf.sample \
 		${STAGEDIR}${PREFIX}/etc
 
 .include <bsd.port.mk>
diff --git a/security/sshguard/files/patch-src_blocker_sshguard__whitelist.c b/security/sshguard/files/patch-src_blocker_sshguard__whitelist.c
new file mode 100644
index 000000000000..6e468872f458
--- /dev/null
+++ b/security/sshguard/files/patch-src_blocker_sshguard__whitelist.c
@@ -0,0 +1,11 @@
+--- src/blocker/sshguard_whitelist.c.orig	2020-12-31 17:06:03 UTC
++++ src/blocker/sshguard_whitelist.c
+@@ -275,7 +275,7 @@ int whitelist_add_block6(const char *restrict address,
+     bitlen = masklen % 8;
+     bitmask = 0xFF << (8 - bitlen);
+     ab.address.ip6.mask.s6_addr[bytelen] = bitmask;
+-    memset(& ab.address.ip6.mask.s6_addr[bytelen+1], 0x00, sizeof(ab.address.ip6.mask.s6_addr) - bytelen);
++    memset(& ab.address.ip6.mask.s6_addr[bytelen+1], 0x00, sizeof(ab.address.ip6.mask.s6_addr) - bytelen - 1);
+ 
+     if (! list_contains(& whitelist, &ab)) {
+         list_append(& whitelist, &ab);