diff --git a/sbin/ipf/Makefile.inc b/sbin/ipf/Makefile.inc
index b3efd6f8eec9..2d7d7b1c71bf 100644
--- a/sbin/ipf/Makefile.inc
+++ b/sbin/ipf/Makefile.inc
@@ -1,5 +1,7 @@
 #	$FreeBSD$
 
+.include <src.opts.mk>
+
 WARNS?=		2
 NO_WFORMAT=
 NO_WARRAY_BOUNDS=
@@ -10,6 +12,12 @@ CFLAGS+=	-I${.CURDIR}/../../../sys
 CFLAGS+=	-I${.CURDIR}/../../../sys/contrib/ipfilter
 CFLAGS+=	-DSTATETOP -D__UIO_EXPOSE
 
+.if ${MK_INET6_SUPPORT} != "no"
+CFLAGS+=	-DUSE_INET6
+.else
+CFLAGS+=	-DNOINET6
+.endif
+
 LIBIPF=		${.OBJDIR}/../libipf/libipf.a
 DPADD+=		${LIBIPF} ${LIBKVM}
 LDADD+=		${LIBIPF} -lkvm
diff --git a/sys/contrib/ipfilter/netinet/ip_compat.h b/sys/contrib/ipfilter/netinet/ip_compat.h
index e88ef88a6a40..6d744683d467 100644
--- a/sys/contrib/ipfilter/netinet/ip_compat.h
+++ b/sys/contrib/ipfilter/netinet/ip_compat.h
@@ -118,6 +118,10 @@ struct  ether_addr {
 #  if defined(INET6) && !defined(USE_INET6)
 #   define USE_INET6
 #  endif
+# else
+#  if !defined(USE_INET6) && !defined(NOINET6)
+#   define	USE_INET6
+#  endif
 # endif
 
 # if defined(_KERNEL)