diff --git a/minix/commands/svrctl/svrctl.c b/minix/commands/svrctl/svrctl.c
index 820fe3891..e9c2280de 100644
--- a/minix/commands/svrctl/svrctl.c
+++ b/minix/commands/svrctl/svrctl.c
@@ -20,7 +20,7 @@ static char *bin_name;
 
 int main (int argc, char *argv[])
 {
-  int param;
+  unsigned long param;
   endpoint_t proc_e = NONE;
   struct sysgetenv sysgetenv;
   char *to_whom, *operation, *what, *value;
diff --git a/minix/commands/tcpstat/tcpstat.c b/minix/commands/tcpstat/tcpstat.c
index f5200a456..2ea8e4fca 100644
--- a/minix/commands/tcpstat/tcpstat.c
+++ b/minix/commands/tcpstat/tcpstat.c
@@ -15,7 +15,6 @@ Created:	June 1995 by Philip Homburg <philip@f-mnx.phicoh.com>
 #include <stdio.h>
 #include <time.h>
 #include <unistd.h>
-#include <sys/svrctl.h>
 #ifndef __minix_vmd
 #include <sys/times.h>
 #endif
diff --git a/minix/commands/udpstat/udpstat.c b/minix/commands/udpstat/udpstat.c
index 54c1c73d1..e893b6c73 100644
--- a/minix/commands/udpstat/udpstat.c
+++ b/minix/commands/udpstat/udpstat.c
@@ -16,7 +16,6 @@ Created:	March 2001 by Philip Homburg <philip@f-mnx.phicoh.com>
 #include <stdio.h>
 #include <time.h>
 #include <unistd.h>
-#include <sys/svrctl.h>
 #ifndef __minix_vmd
 #include <sys/times.h>
 #endif
diff --git a/minix/drivers/clock/readclock/arch/i386/arch_readclock.c b/minix/drivers/clock/readclock/arch/i386/arch_readclock.c
index 9d6b5bd64..07efbca69 100644
--- a/minix/drivers/clock/readclock/arch/i386/arch_readclock.c
+++ b/minix/drivers/clock/readclock/arch/i386/arch_readclock.c
@@ -51,7 +51,6 @@
 #include <minix/com.h>
 #include <minix/log.h>
 #include <machine/cmos.h>
-#include <sys/svrctl.h>
 
 #include "readclock.h"
 
diff --git a/minix/drivers/clock/readclock/readclock.c b/minix/drivers/clock/readclock/readclock.c
index 335f4ffac..2435f2742 100644
--- a/minix/drivers/clock/readclock/readclock.c
+++ b/minix/drivers/clock/readclock/readclock.c
@@ -16,7 +16,6 @@
 #include <minix/com.h>
 #include <minix/type.h>
 #include <minix/safecopies.h>
-#include <sys/svrctl.h>
 
 #include "readclock.h"
 
diff --git a/minix/drivers/storage/at_wini/at_wini.c b/minix/drivers/storage/at_wini/at_wini.c
index 2bfc26a38..c8490e0a8 100644
--- a/minix/drivers/storage/at_wini/at_wini.c
+++ b/minix/drivers/storage/at_wini/at_wini.c
@@ -19,7 +19,6 @@
 #include <sys/ioc_disk.h>
 #include <machine/pci.h>
 #include <sys/mman.h>
-#include <sys/svrctl.h>
 
 /* Variables. */
 
diff --git a/minix/include/minix/ipc.h b/minix/include/minix/ipc.h
index 074c46ba3..3df54efc2 100644
--- a/minix/include/minix/ipc.h
+++ b/minix/include/minix/ipc.h
@@ -596,6 +596,14 @@ typedef struct {
 } mess_lc_readclock_rtcdev;
 _ASSERT_MSG_SIZE(mess_lc_readclock_rtcdev);
 
+typedef struct {
+	unsigned long request;
+	vir_bytes arg;
+
+	uint8_t padding[48];
+} mess_lc_svrctl;
+_ASSERT_MSG_SIZE(mess_lc_svrctl);
+
 typedef struct {
 	vir_bytes name;
 	size_t len;
@@ -1314,14 +1322,6 @@ typedef struct {
 } mess_lsys_sched_scheduling_stop;
 _ASSERT_MSG_SIZE(mess_lsys_sched_scheduling_stop);
 
-typedef struct {
-	int request;
-	vir_bytes arg;
-
-	uint8_t padding[48];
-} mess_lsys_svrctl;
-_ASSERT_MSG_SIZE(mess_lsys_svrctl);
-
 typedef struct {
 	int request;
 	int fkeys;
@@ -2095,6 +2095,7 @@ typedef struct {
 		mess_lc_pm_time		m_lc_pm_time;
 		mess_lc_pm_waitpid	m_lc_pm_waitpid;
 		mess_lc_readclock_rtcdev m_lc_readclock_rtcdev;
+		mess_lc_svrctl		m_lc_svrctl;
 		mess_lc_vfs_chown	m_lc_vfs_chown;
 		mess_lc_vfs_close	m_lc_vfs_close;
 		mess_lc_vfs_creat	m_lc_vfs_creat;
@@ -2174,7 +2175,6 @@ typedef struct {
 		mess_lsys_pm_srv_fork	m_lsys_pm_srv_fork;
 		mess_lsys_sched_scheduling_start m_lsys_sched_scheduling_start;
 		mess_lsys_sched_scheduling_stop m_lsys_sched_scheduling_stop;
-		mess_lsys_svrctl	m_lsys_svrctl;
 		mess_lsys_tty_fkey_ctl	m_lsys_tty_fkey_ctl;
 		mess_lsys_vfs_checkperms m_lsys_vfs_checkperms;
 		mess_lsys_vfs_copyfd	m_lsys_vfs_copyfd;
diff --git a/minix/include/sys/svrctl.h b/minix/include/sys/svrctl.h
index 88746d4b1..4b189444f 100644
--- a/minix/include/sys/svrctl.h
+++ b/minix/include/sys/svrctl.h
@@ -13,12 +13,15 @@ Created:	Feb 15, 1994 by Philip Homburg <philip@cs.vu.nl>
 #include <minix/ioctl.h>
 
 /* PM controls. */
-#define PMGETPARAM	_IOW('M',  5, struct sysgetenv)
-#define PMSETPARAM	_IOR('M',  7, struct sysgetenv)
+#define PMGETPARAM	_IOWR('P',  0, struct sysgetenv)
+#define PMSETPARAM	_IOW('P',  1, struct sysgetenv)
+
+#define OPMGETPARAM	_IOW('M',  5, struct sysgetenv)	/* old, phasing out */
+#define OPMSETPARAM	_IOR('M',  7, struct sysgetenv)	/* old, phasing out */
 
 /* VFS controls */
-#define VFSSETPARAM	_IOR('M', 130, struct sysgetenv)
-#define VFSGETPARAM	_IOR('M', 131, struct sysgetenv)
+#define VFSGETPARAM	_IOWR('F', 0, struct sysgetenv)
+#define VFSSETPARAM	_IOW('F', 1, struct sysgetenv)
 
 struct sysgetenv {
 	char		*key;		/* Name requested. */
@@ -27,6 +30,6 @@ struct sysgetenv {
 	size_t		vallen;		/* Size of return data buffer. */
 };
 
-int svrctl(int _request, void *_data);
+int svrctl(unsigned long _request, void *_data);
 
 #endif /* _SYS__SVRCTL_H */
diff --git a/minix/lib/libc/sys/svrctl.c b/minix/lib/libc/sys/svrctl.c
index b93af6cea..67649f853 100644
--- a/minix/lib/libc/sys/svrctl.c
+++ b/minix/lib/libc/sys/svrctl.c
@@ -6,22 +6,19 @@
 #include <string.h>
 #include <sys/svrctl.h>
 
-int svrctl(int request, void *argp)
+int svrctl(unsigned long request, void *argp)
 {
 	message m;
 
 	memset(&m, 0, sizeof(m));
-	m.m_lsys_svrctl.request = request;
-	m.m_lsys_svrctl.arg = argp;
+	m.m_lc_svrctl.request = request;
+	m.m_lc_svrctl.arg = (vir_bytes)argp;
 
-	switch ((request >> 8) & 0xFF) {
-	case 'M':
-	case 'S':
-		/* PM handles calls for itself and the kernel. */
+	switch (IOCGROUP(request)) {
+	case 'M': /* old, phasing out */
+	case 'P': /* to PM */
 		return _syscall(PM_PROC_NR, PM_SVRCTL, &m);
-	case 'F':
-	case 'I':
-		/* VFS handles calls for itself and inet. */
+	case 'F': /* to VFS */
 		return _syscall(VFS_PROC_NR, VFS_SVRCTL, &m);
 	default:
 		errno = EINVAL;
diff --git a/minix/net/inet/inet.c b/minix/net/inet/inet.c
index c18dd58cc..1c6aecb67 100644
--- a/minix/net/inet/inet.c
+++ b/minix/net/inet/inet.c
@@ -8,7 +8,6 @@ Copyright 1995 Philip Homburg
 
 #include <fcntl.h>
 #include <unistd.h>
-#include <sys/svrctl.h>
 #include <minix/ds.h>
 #include <minix/endpoint.h>
 #include <minix/chardriver.h>
diff --git a/minix/net/inet/qp.c b/minix/net/inet/qp.c
index df09c856b..7350a0931 100644
--- a/minix/net/inet/qp.c
+++ b/minix/net/inet/qp.c
@@ -9,7 +9,6 @@ Created:	June 1995 by Philip Homburg <philip@f-mnx.phicoh.com>
 #include "inet.h"
 #include "generic/assert.h"
 
-#include <sys/svrctl.h>
 #include "queryparam.h"
 
 #include "generic/buf.h"
diff --git a/minix/net/lwip/lwip.c b/minix/net/lwip/lwip.c
index 0edd7af51..f7b5af051 100644
--- a/minix/net/lwip/lwip.c
+++ b/minix/net/lwip/lwip.c
@@ -1,6 +1,5 @@
 #include <unistd.h>
 #include <minix/timers.h>
-#include <sys/svrctl.h>
 #include <minix/ds.h>
 #include <minix/endpoint.h>
 #include <errno.h>
diff --git a/minix/servers/pm/misc.c b/minix/servers/pm/misc.c
index 8014f63d7..0b594376f 100644
--- a/minix/servers/pm/misc.c
+++ b/minix/servers/pm/misc.c
@@ -295,9 +295,10 @@ int do_getsetpriority()
 /*===========================================================================*
  *				do_svrctl				     *
  *===========================================================================*/
-int do_svrctl()
+int do_svrctl(void)
 {
-  int s, req;
+  unsigned long req;
+  int s;
   vir_bytes ptr;
 #define MAX_LOCAL_PARAMS 2
   static struct {
@@ -306,14 +307,16 @@ int do_svrctl()
   } local_param_overrides[MAX_LOCAL_PARAMS];
   static int local_params = 0;
 
-  req = m_in.m_lsys_svrctl.request;
-  ptr = m_in.m_lsys_svrctl.arg;
+  req = m_in.m_lc_svrctl.request;
+  ptr = m_in.m_lc_svrctl.arg;
 
-  /* Is the request indeed for the PM? */
-  if (((req >> 8) & 0xFF) != 'M') return(EINVAL);
+  /* Is the request indeed for the PM? ('M' is old and being phased out) */
+  if (IOCGROUP(req) != 'P' && IOCGROUP(req) != 'M') return(EINVAL);
 
   /* Control operations local to the PM. */
   switch(req) {
+  case OPMSETPARAM:
+  case OPMGETPARAM:
   case PMSETPARAM:
   case PMGETPARAM: {
       struct sysgetenv sysgetenv;
@@ -327,7 +330,7 @@ int do_svrctl()
               sizeof(sysgetenv)) != OK) return(EFAULT);  
 
       /* Set a param override? */
-      if (req == PMSETPARAM) {
+      if (req == PMSETPARAM || req == OPMSETPARAM) {
   	if (local_params >= MAX_LOCAL_PARAMS) return ENOSPC;
   	if (sysgetenv.keylen <= 0
   	 || sysgetenv.keylen >=
diff --git a/minix/servers/vfs/misc.c b/minix/servers/vfs/misc.c
index 65d4b8630..8652007ca 100644
--- a/minix/servers/vfs/misc.c
+++ b/minix/servers/vfs/misc.c
@@ -776,12 +776,13 @@ void pm_setsid(endpoint_t proc_e)
  *===========================================================================*/
 int do_svrctl(void)
 {
-  unsigned int svrctl;
+  unsigned long svrctl;
   vir_bytes ptr;
 
-  svrctl = job_m_in.m_lsys_svrctl.request;
-  ptr = job_m_in.m_lsys_svrctl.arg;
-  if (((svrctl >> 8) & 0xFF) != 'M') return(EINVAL);
+  svrctl = job_m_in.m_lc_svrctl.request;
+  ptr = job_m_in.m_lc_svrctl.arg;
+
+  if (IOCGROUP(svrctl) != 'F') return(EINVAL);
 
   switch (svrctl) {
     case VFSSETPARAM: