diff --git a/include/sys/types.h b/include/sys/types.h
index 9dcf4fd9d..4e645f4e4 100644
--- a/include/sys/types.h
+++ b/include/sys/types.h
@@ -114,12 +114,14 @@ typedef u32_t		big_nlink_t;
 typedef u32_t		big_uid_t;
 
 
+#ifdef _MINIX
 /* some Minix specific types that do not conflict with posix */
 typedef u32_t zone_t;      /* zone number */
 typedef u32_t block_t;     /* block number */
 typedef u32_t bit_t;       /* bit number in a bit map */
 typedef u16_t zone1_t;     /* zone number for V1 file systems */
 typedef u32_t bitchunk_t; /* collection of bits in a bitmap */
+#endif
 
 /* ANSI C makes writing down the promotion of unsigned types very messy.  When
  * sizeof(short) == sizeof(int), there is no promotion, so the type stays
diff --git a/kernel/Makefile b/kernel/Makefile
index d385c26d4..26fef605e 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -15,7 +15,7 @@ LDADD+=	-ltimers -lsys -lexec
 
 CFLAGS += -D__kernel__ 
 
-CPPFLAGS+= -fno-stack-protector -D_NETBSD_SOURCE
+CPPFLAGS+= -fno-stack-protector -D_NETBSD_SOURCE -D_MINIX
 LDFLAGS+= -T $(LINKERSCRIPT)
 LDFLAGS+= -nostdlib -L${DESTDIR}/${LIBDIR}
 LDADD+= -lminlib
diff --git a/sys/arch/i386/stand/boot/biosboot/Makefile b/sys/arch/i386/stand/boot/biosboot/Makefile
index 2d3c99888..7d697f331 100644
--- a/sys/arch/i386/stand/boot/biosboot/Makefile
+++ b/sys/arch/i386/stand/boot/biosboot/Makefile
@@ -3,4 +3,6 @@
 PROG=	boot_monitor
 CLEANFILES= lib
 
+CPPFLAGS+= -D_MINIX
+
 .include <../Makefile.boot>
diff --git a/sys/arch/i386/stand/bootxx/bootxx_ext2fs/Makefile b/sys/arch/i386/stand/bootxx/bootxx_ext2fs/Makefile
index 6110228d9..2a6418aa3 100644
--- a/sys/arch/i386/stand/bootxx/bootxx_ext2fs/Makefile
+++ b/sys/arch/i386/stand/bootxx/bootxx_ext2fs/Makefile
@@ -2,5 +2,6 @@
 
 FS=ext2fs
 CLEANFILES= lib
+CPPFLAGS+= -D_MINIX
 
 .include <../Makefile.bootxx>
diff --git a/usr.sbin/mkfs.mfs/Makefile b/usr.sbin/mkfs.mfs/Makefile
index 169888e6b..c9a462e83 100644
--- a/usr.sbin/mkfs.mfs/Makefile
+++ b/usr.sbin/mkfs.mfs/Makefile
@@ -3,6 +3,8 @@ SRCS=	mkfs.c
 BINDIR=	/sbin
 MAN=
 
+CPPFLAGS+= -D_MINIX
+
 LDADD?= -lminlib -lcompat_minix
 
 .include <bsd.prog.mk>