diff --git a/mail/libsrs_alt/Makefile b/mail/libsrs_alt/Makefile
index 65b5f0694800..f69e06ce8acf 100644
--- a/mail/libsrs_alt/Makefile
+++ b/mail/libsrs_alt/Makefile
@@ -1,35 +1,40 @@
 PORTNAME=		libsrs_alt
 DISTVERSION=		1.0
 PORTREVISION=		2
 CATEGORIES=		mail
 MASTER_SITES=		http://opsec.eu/src/srs/
 
 MAINTAINER=		pi@FreeBSD.org
 COMMENT=		Sender Rewriting Scheme C Implementation
 WWW=		https://opsec.eu/src/srs/
 
 USES=			libtool tar:bzip2
 USE_LDCONFIG=		yes
-SHLIB_MAJOR=		1
+
 GNU_CONFIGURE=		yes
 
 PLIST_SUB=		SHLIB_MAJOR="${SHLIB_MAJOR}"
 
 OPTIONS_DEFINE=		COMPAT_BASE64
+
 COMPAT_BASE64_DESC=	MTA Friendly base64 compatibility mode
 
+COMPAT_BASE64_CONFIGURE_ON=	--with-base64compat
+
+SHLIB_MAJOR=		1
+
 .include <bsd.port.options.mk>
 
-.if ${PORT_OPTIONS:MCOMPAT_BASE64}
-CONFIGURE_ARGS+=	--with-base64compat
+.if ${OPSYS} == FreeBSD && ( ${OSVERSION} >= 1400091 || ( ${OSVERSION} >= 1302507 && ${OSVERSION} < 1400000 ))
+CFLAGS+=	-Wno-error=incompatible-function-pointer-types
 .endif
 
 post-patch:
 	@${REINPLACE_CMD} -E 's,^(test_LDFLAGS.*$$),\1 -lcompat,' \
 		${WRKSRC}/Makefile.in
 
 post-install:
 	${MV} ${STAGEDIR}${PREFIX}/bin/srs ${STAGEDIR}${PREFIX}/bin/srs_alt
 	${STRIP_CMD} ${STAGEDIR}${PREFIX}/lib/libsrs_alt.so.1.0.0
 
 .include <bsd.port.mk>