diff --git a/devel/libowfat/Makefile b/devel/libowfat/Makefile
index c10da4af7947..98fa33d62fea 100644
--- a/devel/libowfat/Makefile
+++ b/devel/libowfat/Makefile
@@ -1,42 +1,43 @@
 PORTNAME=	libowfat
 PORTVERSION=	0.32
+PORTREVISION=	1
 CATEGORIES=	devel
 MASTER_SITES=	https://www.fefe.de/libowfat/
 
 MAINTAINER=	ports@FreeBSD.org
 COMMENT=	General purpose library based on code by D. J. Bernstein
 WWW=		https://www.fefe.de/libowfat/
 
 LICENSE=	GPLv2
 LICENSE_FILE=	${WRKSRC}/COPYING
 
 USES=		gmake tar:xz
 MAKEFILE=	GNUmakefile
 ALL_TARGET=	dep all
 
 OPTIONS_DEFINE=	OPTIMIZED_CFLAGS
 OPTIONS_DEFAULT=	OPTIMIZED_CFLAGS
 
 .include <bsd.port.pre.mk>
 
 MAKE_ENV+=	INSTALL="${INSTALL}"
 
 .include "${FILESDIR}/manpages"
 
 .if ${PORT_OPTIONS:MOPTIMIZED_CFLAGS}
 CFLAGS+=	-O2 -fomit-frame-pointer
 .endif
 
 post-extract:
 	@${MKDIR} ${WRKSRC}/man
 # Manual pages clash with other programs; prepend libowfat_ to them.
 .for i in ${MANPAGES}
 	@${MV} ${WRKSRC}/*/${i:S/libowfat_//} ${WRKSRC}/man/${i}
 .endfor
 
 post-patch:
 # Clang cries when void functions return a value
 	${REINPLACE_CMD} -e '56s|return ||' ${WRKSRC}/CAS.h
 	${REINPLACE_CMD} -e "s|STAGEDIR|${STAGEDIR}|g" ${WRKSRC}/GNUmakefile
 
 .include <bsd.port.post.mk>
diff --git a/devel/libowfat/files/patch-io_internal.h b/devel/libowfat/files/patch-io_internal.h
new file mode 100644
index 000000000000..30d70f2eaf13
--- /dev/null
+++ b/devel/libowfat/files/patch-io_internal.h
@@ -0,0 +1,11 @@
+--- io_internal.h.orig	2021-12-03 03:57:20.158865000 +0100
++++ io_internal.h	2021-12-03 03:57:28.438206000 +0100
+@@ -83,7 +83,7 @@
+ my_extern long first_readable;
+ my_extern long first_writeable;
+ 
+-my_extern long first_deferred;
++extern long first_deferred;
+ 
+ my_extern enum __io_waitmode {
+   UNDECIDED,