diff --git a/mail/xmailbox/Makefile b/mail/xmailbox/Makefile
index 7bc0daa4840a..340b17166659 100644
--- a/mail/xmailbox/Makefile
+++ b/mail/xmailbox/Makefile
@@ -1,26 +1,34 @@
 PORTNAME=	xmailbox
 PORTVERSION=	2.5
 PORTREVISION=	2
 CATEGORIES=	mail
 MASTER_SITES=	XCONTRIB/applications
 
 MAINTAINER=	ports@FreeBSD.org
 COMMENT=	Mailbox checker with sound and animation for X Window System
 
 USES=		imake xorg
 USE_XORG=	xaw
 
 OPTIONS_DEFINE=	DOCS
 
+.include <bsd.port.options.mk>
+
+.if ${OPSYS} == FreeBSD && ${OSVERSION} >= 1400091
+CFLAGS+=	-Wno-error=incompatible-function-pointer-types
+.endif
+
 post-patch:
 	@${REINPLACE_CMD} -e "s|%%PREFIX%%|${PREFIX}|g" ${WRKSRC}/XMailbox.ad
 
 post-install:
 	@${MKDIR} ${STAGEDIR}${DATADIR}
 	${INSTALL_DATA} ${WRKSRC}/dingdong.au ${STAGEDIR}${DATADIR}
 	${INSTALL_DATA} ${WRKSRC}/ugotmail.au ${STAGEDIR}${DATADIR}
+
+post-install-DOCS-on:
 	@${MKDIR} ${STAGEDIR}${DOCSDIR}
 	${INSTALL_DATA} ${WRKSRC}/DISCLAIMER ${STAGEDIR}${DOCSDIR}
 	${INSTALL_DATA} ${WRKSRC}/README ${STAGEDIR}${DOCSDIR}
 
 .include <bsd.port.mk>