--- Makefile.orig	2014-08-15 18:26:37.000000000 -0400
+++ Makefile	2014-08-15 18:27:35.000000000 -0400
@@ -38,7 +38,7 @@
 CFLAGS+= -DHAVE_CONFIG_H
 CFLAGS+= -D_U_="__attribute__((unused))"
 
-.if ${MK_INET6_SUPPORT} != "no"
+.if empty(MK_INET6_SUPPORT:Mno)
 SRCS+=	print-ip6.c print-ip6opts.c print-mobility.c print-ripng.c \
 	print-icmp6.c print-frag6.c print-rt6.c print-ospf6.c print-dhcp6.c
 CFLAGS+=	-DINET6
@@ -49,14 +49,14 @@
 
 DPADD=	${LIBL} ${LIBPCAP}
 LDADD=	-ll -lpcap
-.if ${MK_OPENSSL} != "no" && !defined(RELEASE_CRUNCH)
+.if empty(MK_OPENSSL:Mno) && !defined(RELEASE_CRUNCH)
 DPADD+= ${LIBCRYPTO}
 LDADD+= -lcrypto
 CFLAGS+= -I${DESTDIR}/usr/include/openssl
 CFLAGS+= -DHAVE_LIBCRYPTO -DHAVE_RC5_H -DHAVE_CAST_H -DHAVE_OPENSSL_EVP_H
 .endif
 
-.if ${MK_PF} != "no"
+.if empty(MK_PF:Mno)
 SRCS+=	print-pflog.c
 CFLAGS+= -DHAVE_NET_PFVAR_H
 .endif