diff --git a/commands/mdb/misc.c b/commands/mdb/misc.c
index f1c732479..a347c246f 100644
--- a/commands/mdb/misc.c
+++ b/commands/mdb/misc.c
@@ -7,6 +7,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/stat.h>
+#include <sys/param.h>
 #define ptrace mdbtrace
 #include <sys/ptrace.h>
 #include "proto.h"
diff --git a/commands/mdocml/term_ps.c b/commands/mdocml/term_ps.c
index b6e0e2b5d..56d1be240 100644
--- a/commands/mdocml/term_ps.c
+++ b/commands/mdocml/term_ps.c
@@ -54,9 +54,6 @@
 	} while (/* CONSTCOND */ 0)
 
 
-#ifndef MAX
-#define MAX(x,y) ((x) > (y) ? (x) : (y))
-#endif
 static	void		  ps_letter(struct termp *, char);
 static	void		  ps_begin(struct termp *);
 static	void		  ps_end(struct termp *);
diff --git a/commands/pkg_install/info/show.c b/commands/pkg_install/info/show.c
index 99056739a..db4221854 100644
--- a/commands/pkg_install/info/show.c
+++ b/commands/pkg_install/info/show.c
@@ -64,6 +64,9 @@ __RCSID("$NetBSD: show.c,v 1.30 2009/08/02 17:56:45 joerg Exp $");
 #if HAVE_ERR_H
 #include <err.h>
 #endif
+#if HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
 
 #include "defs.h"
 #include "lib.h"
diff --git a/include/minix/const.h b/include/minix/const.h
index 393f4b4be..343a8a726 100644
--- a/include/minix/const.h
+++ b/include/minix/const.h
@@ -91,10 +91,6 @@
 #define WRITING            1	/* copy data from user */
 #define HAVE_SCATTERED_IO  1	/* scattered I/O is now standard */
 
-/* Macros. */
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
-
 /* Memory is allocated in clicks. */
 #if (CHIP == INTEL)
 #define CLICK_SIZE      4096	/* unit in which memory is allocated */
diff --git a/include/minix/driver.h b/include/minix/driver.h
index 71b888a9c..139a00ca9 100644
--- a/include/minix/driver.h
+++ b/include/minix/driver.h
@@ -26,6 +26,7 @@
 #include <limits.h>
 #include <stddef.h>
 #include <errno.h>
+#include <sys/param.h>
 
 #include <minix/partition.h>
 #include <minix/u64.h>
diff --git a/include/minix/drivers.h b/include/minix/drivers.h
index 39a5b8320..2d1e49702 100644
--- a/include/minix/drivers.h
+++ b/include/minix/drivers.h
@@ -36,5 +36,6 @@
 #include <stddef.h>
 #include <errno.h>
 #include <unistd.h>
+#include <sys/param.h>
 
 #endif
diff --git a/include/sys/param.h b/include/sys/param.h
index 13b2c6bc8..2e14ec924 100644
--- a/include/sys/param.h
+++ b/include/sys/param.h
@@ -12,4 +12,8 @@ sys/param.h
 #define NGROUPS		8	/* max number of supplementary groups */
 #define MAXPATHLEN	__MINIX_PATH_MAX
 
+/* Macros for min/max. */
+#define MIN(a,b)        ((/*CONSTCOND*/(a)<(b))?(a):(b))
+#define MAX(a,b)        ((/*CONSTCOND*/(a)>(b))?(a):(b))
+
 #endif /* __SYS_PARAM_H__ */
diff --git a/kernel/kernel.h b/kernel/kernel.h
index 968dbce7a..dce3c5642 100644
--- a/kernel/kernel.h
+++ b/kernel/kernel.h
@@ -40,6 +40,7 @@
 #include <minix/sysutil.h>	/* MINIX utility library functions */
 #include <timers.h>		/* watchdog timer management */
 #include <errno.h>		/* return codes and error numbers */
+#include <sys/param.h>
 
 /* Important kernel header files. */
 #include "config.h"		/* configuration, MUST be first */
diff --git a/lib/libc/db/btree/bt_overflow.c b/lib/libc/db/btree/bt_overflow.c
index 1d77be9ca..caf37bad7 100644
--- a/lib/libc/db/btree/bt_overflow.c
+++ b/lib/libc/db/btree/bt_overflow.c
@@ -54,9 +54,6 @@ __RCSID("$NetBSD: bt_overflow.c,v 1.16 2008/09/11 12:58:00 joerg Exp $");
 #include <db.h>
 #include "btree.h"
 
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
-
 /*
  * Big key/data code.
  *
diff --git a/lib/libc/db/btree/bt_utils.c b/lib/libc/db/btree/bt_utils.c
index 59503c34e..fe0640c7c 100644
--- a/lib/libc/db/btree/bt_utils.c
+++ b/lib/libc/db/btree/bt_utils.c
@@ -51,9 +51,6 @@ __RCSID("$NetBSD: bt_utils.c,v 1.13 2008/09/10 17:52:35 joerg Exp $");
 #include <db.h>
 #include "btree.h"
 
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
-
 /*
  * __bt_ret --
  *	Build return key/data pair.
diff --git a/lib/libc/db/hash/hash.c b/lib/libc/db/hash/hash.c
index 3338885ea..2ff1d0e74 100644
--- a/lib/libc/db/hash/hash.c
+++ b/lib/libc/db/hash/hash.c
@@ -76,9 +76,6 @@ __RCSID("$NetBSD: hash.c,v 1.31 2009/02/12 06:35:54 lukem Exp $");
 #define _DIAGASSERT
 #endif
 
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
-
 static int   alloc_segs(HTAB *, int);
 static int   flush_meta(HTAB *);
 static int   hash_access(HTAB *, ACTION, DBT *, DBT *);
diff --git a/lib/libc/db/hash/hash_bigkey.c b/lib/libc/db/hash/hash_bigkey.c
index be31e3db2..790168d1d 100644
--- a/lib/libc/db/hash/hash_bigkey.c
+++ b/lib/libc/db/hash/hash_bigkey.c
@@ -76,9 +76,6 @@ __RCSID("$NetBSD: hash_bigkey.c,v 1.23 2009/02/12 06:33:13 lukem Exp $");
 #define _DIAGASSERT
 #endif
 
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
-
 static int collect_key(HTAB *, BUFHEAD *, int, DBT *, int);
 static int collect_data(HTAB *, BUFHEAD *, int, int);
 
diff --git a/lib/libc/db/hash/hash_buf.c b/lib/libc/db/hash/hash_buf.c
index 98a868164..44d91f3b5 100644
--- a/lib/libc/db/hash/hash_buf.c
+++ b/lib/libc/db/hash/hash_buf.c
@@ -97,8 +97,6 @@ static BUFHEAD *newbuf(HTAB *, uint32_t, BUFHEAD *);
 #define _DIAGASSERT assert
 #endif
 
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
 /*
  * We are looking for a buffer with address "addr".  If prev_bp is NULL, then
  * address is a bucket index.  If prev_bp is not NULL, then it points to the
diff --git a/lib/libc/other/fts.c b/lib/libc/other/fts.c
index f9dc37b15..843925eff 100644
--- a/lib/libc/other/fts.c
+++ b/lib/libc/other/fts.c
@@ -39,10 +39,6 @@ static char sccsid[] = "@(#)fts.c	8.6 (Berkeley) 8/14/94";
 #endif /* LIBC_SCCS and not lint */
 #endif
 
-#define MAX(a, b)   ((a) > (b) ? (a) : (b))
-#define MIN(a, b)   ((a) < (b) ? (a) : (b))
-
-
 #define _POSIX_SOURCE 1
 #define _MINIX 1
 
diff --git a/lib/libc/other/vectorio.c b/lib/libc/other/vectorio.c
index 1e59e6959..3b3d5b111 100644
--- a/lib/libc/other/vectorio.c
+++ b/lib/libc/other/vectorio.c
@@ -4,14 +4,13 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/param.h>
 #include <sys/uio.h>
 #include <unistd.h>
 
 #define VECTORIO_READ	1
 #define VECTORIO_WRITE	2
 
-#define MIN(x, y) (((x) < (y)) ? (x) : (y))
-
 static ssize_t vectorio_buffer(int fildes, const struct iovec *iov, 
 	int iovcnt, int readwrite, ssize_t totallen)
 {
diff --git a/lib/libsys/sys_getinfo.c b/lib/libsys/sys_getinfo.c
index bb408d7bb..cbfc94bbd 100644
--- a/lib/libsys/sys_getinfo.c
+++ b/lib/libsys/sys_getinfo.c
@@ -1,6 +1,6 @@
 
 #include <string.h>
-
+#include <sys/param.h>
 #include "syslib.h"
 
 /*===========================================================================*
diff --git a/servers/ds/inc.h b/servers/ds/inc.h
index c1bf05ace..34064bd26 100644
--- a/servers/ds/inc.h
+++ b/servers/ds/inc.h
@@ -9,6 +9,7 @@
 
 #include <ansi.h>
 #include <sys/types.h>
+#include <sys/param.h>
 #include <limits.h>
 #include <errno.h>
 #include <regex.h>
diff --git a/servers/ext2/read.c b/servers/ext2/read.c
index d908beecf..0e177eb79 100644
--- a/servers/ext2/read.c
+++ b/servers/ext2/read.c
@@ -13,6 +13,7 @@
 #include "super.h"
 #include <minix/vfsif.h>
 #include <assert.h>
+#include <sys/param.h>
 
 
 FORWARD _PROTOTYPE( struct buf *rahead, (struct inode *rip, block_t baseblock,
diff --git a/servers/hgfs/inc.h b/servers/hgfs/inc.h
index 5f983a598..7e2c6ec31 100644
--- a/servers/hgfs/inc.h
+++ b/servers/hgfs/inc.h
@@ -13,6 +13,7 @@
 #include <minix/vfsif.h>
 #include <minix/syslib.h>
 #include <minix/sysutil.h>
+#include <sys/param.h>
 
 #if DEBUG
 #define dprintf(x) printf x
diff --git a/servers/iso9660fs/inc.h b/servers/iso9660fs/inc.h
index 683ab65a3..26d99a82b 100644
--- a/servers/iso9660fs/inc.h
+++ b/servers/iso9660fs/inc.h
@@ -26,6 +26,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <signal.h>
+#include <sys/param.h>
 
 #include "proto.h"
 #include "super.h"
diff --git a/servers/pm/pm.h b/servers/pm/pm.h
index c915aa8ae..579757e63 100644
--- a/servers/pm/pm.h
+++ b/servers/pm/pm.h
@@ -20,6 +20,7 @@
 
 #include <limits.h>
 #include <errno.h>
+#include <sys/param.h>
 
 #include "const.h"
 #include "type.h"
diff --git a/servers/rs/inc.h b/servers/rs/inc.h
index 3d05fdf67..9c4cbba52 100644
--- a/servers/rs/inc.h
+++ b/servers/rs/inc.h
@@ -49,6 +49,7 @@
 #include <unistd.h>
 #include <signal.h>
 #include <assert.h>
+#include <sys/param.h>
 
 #include "proto.h"
 #include "const.h"
diff --git a/servers/vm/exec.c b/servers/vm/exec.c
index 6c6895e2e..2b077b7a5 100644
--- a/servers/vm/exec.c
+++ b/servers/vm/exec.c
@@ -20,6 +20,7 @@
 #include <assert.h>
 #include <env.h>
 #include <pagetable.h>
+#include <sys/param.h>
 
 #include "glo.h"
 #include "proto.h"
diff --git a/servers/vm/region.c b/servers/vm/region.c
index 752f1382d..3fd760fa4 100644
--- a/servers/vm/region.c
+++ b/servers/vm/region.c
@@ -19,6 +19,7 @@
 #include <assert.h>
 #include <stdint.h>
 #include <memory.h>
+#include <sys/param.h>
 
 #include "vm.h"
 #include "proto.h"
diff --git a/servers/vm/utility.c b/servers/vm/utility.c
index b7f594647..86c2a118d 100644
--- a/servers/vm/utility.c
+++ b/servers/vm/utility.c
@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <memory.h>
 #include <assert.h>
+#include <sys/param.h>
 
 #include "proto.h"
 #include "glo.h"
diff --git a/test/test50.c b/test/test50.c
index 7da55f016..d83c2ba2b 100644
--- a/test/test50.c
+++ b/test/test50.c
@@ -1,6 +1,7 @@
 /* Tests for truncate(2) call family - by D.C. van Moolenbroek */
 #define _POSIX_SOURCE 1
 #include <sys/stat.h>
+#include <sys/param.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <assert.h>
@@ -12,10 +13,6 @@
 #define TESTSIZE 4096
 #define THRESHOLD 1048576
 
-#ifndef MIN
-#define MIN(x,y) (((x)<(y))?(x):(y))
-#endif
-
 #include "common.c"
 
 _PROTOTYPE(int main, (int argc, char *argv[]));