diff --git a/check.t b/check.t
index bf5465c..389dc1e 100644
--- a/check.t
+++ b/check.t
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.160 2008/03/23 20:54:29 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.161 2008/03/23 22:09:57 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -7,7 +7,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R33 2008/03/05
+	@(#)MIRBSD KSH R33 2008/03/23
 description:
 	Check version of shell.
 category: pdksh
diff --git a/misc.c b/misc.c
index 34d59c3..fb7c2d9 100644
--- a/misc.c
+++ b/misc.c
@@ -6,7 +6,7 @@
 #include <grp.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.68 2008/02/27 01:00:09 tg Exp $\t"
+__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.69 2008/03/23 22:09:58 tg Exp $\t"
 	MKSH_SH_H_ID);
 
 #undef USE_CHVT
@@ -1337,28 +1337,32 @@ chvt(const char *fn)
 	struct stat sb;
 	int fd;
 
-	if (stat(fn, &sb)) {
-		memcpy(dv, "/dev/ttyC", 9);
-		strlcpy(dv + 9, fn, 20 - 9);
-		if (stat(dv, &sb)) {
-			strlcpy(dv + 8, fn, 20 - 8);
-			if (stat(dv, &sb))
-				errorf("chvt: can't find tty %s", fn);
+	if (*fn == '-') {
+		memcpy(dv, "-/dev/null", sizeof ("-/dev/null"));
+		fn = dv + 1;
+	} else {
+		if (stat(fn, &sb)) {
+			memcpy(dv, "/dev/ttyC", 9);
+			strlcpy(dv + 9, fn, 20 - 9);
+			if (stat(dv, &sb)) {
+				strlcpy(dv + 8, fn, 20 - 8);
+				if (stat(dv, &sb))
+					errorf("chvt: can't find tty %s", fn);
+			}
+			fn = dv;
 		}
-		fn = dv;
-	}
-	if (!(sb.st_mode & S_IFCHR))
-		errorf("chvt: not a char device: %s", fn);
-	if ((sb.st_uid != 0) && chown(fn, 0, 0))
-		warningf(false, "chvt: cannot chown root %s", fn);
-	if (((sb.st_mode & 07777) != 0600) && chmod(fn, 0600))
-		warningf(false, "chvt: cannot chmod 0600 %s", fn);
+		if (!(sb.st_mode & S_IFCHR))
+			errorf("chvt: not a char device: %s", fn);
+		if ((sb.st_uid != 0) && chown(fn, 0, 0))
+			warningf(false, "chvt: cannot chown root %s", fn);
+		if (((sb.st_mode & 07777) != 0600) && chmod(fn, 0600))
+			warningf(false, "chvt: cannot chmod 0600 %s", fn);
 #if HAVE_REVOKE
-	if (revoke(fn))
+		if (revoke(fn))
 #endif
-		warningf(false, "chvt: cannot revoke %s, new shell is"
-		    " potentially insecure", fn);
-
+			warningf(false, "chvt: cannot revoke %s, new shell is"
+			    " potentially insecure", fn);
+	}
 	if ((fd = open(fn, O_RDWR)) == -1) {
 		sleep(1);
 		if ((fd = open(fn, O_RDWR)) == -1)
@@ -1374,7 +1378,7 @@ chvt(const char *fn)
 	}
 	if (setsid() == -1)
 		errorf("chvt: setsid failed");
-	if (ioctl(fd, TIOCSCTTY, NULL) == -1)
+	if ((fn != dv + 1) && ioctl(fd, TIOCSCTTY, NULL) == -1)
 		errorf("chvt: TIOCSCTTY failed");
 	dup2(fd, 0);
 	dup2(fd, 1);
diff --git a/mksh.1 b/mksh.1
index 2ebb645..2dfaa42 100644
--- a/mksh.1
+++ b/mksh.1
@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.113 2008/03/04 00:09:34 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.114 2008/03/23 22:09:58 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.120 2007/05/31 20:47:44 otto Exp $
 .\"-
 .\" Try to make GNU groff and AT&T nroff more compatible
@@ -30,7 +30,7 @@
 .el .xD \\$1 \\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8
 ..
 .\"-
-.Dd $Mdocdate: March 4 2008 $
+.Dd $Mdocdate: March 23 2008 $
 .Dt MKSH 1
 .Os MirBSD
 .Sh NAME
@@ -41,7 +41,7 @@
 .Nm
 .Bk -words
 .Op Fl +abCefhiklmnprUuvXx
-.Op Fl T Ar /dev/ttyCn
+.Op Fl T Ar /dev/ttyCn | \-
 .Op Fl +o Ar option
 .Oo Fl c Ar string \*(Ba Fl s \*(Ba
 .Ar \ file\ \&
@@ -171,6 +171,9 @@ on the
 .Xr tty 4
 device given.
 Superuser only.
+If
+.Ar tty
+is a dash, detach from controlling terminal (daemonise) instead.
 .El
 .Pp
 In addition to the above, the options described in the
@@ -5452,7 +5455,7 @@ and many other persons, and is currently maintained by
 .An Thorsten Glaser Aq tg@mirbsd.de .
 .Sh BUGS
 This document attempts to describe
-.Nm mksh\ R33
+.Nm mksh\ R33b
 and up,
 compiled without any options impacting functionality, such as
 .Dv MKSH_SMALL ,
diff --git a/sh.h b/sh.h
index 82c497b..4c1b9c5 100644
--- a/sh.h
+++ b/sh.h
@@ -8,8 +8,8 @@
 /*	$OpenBSD: c_test.h,v 1.4 2004/12/20 11:34:26 otto Exp $	*/
 /*	$OpenBSD: tty.h,v 1.5 2004/12/20 11:34:26 otto Exp $	*/
 
-#define MKSH_SH_H_ID "$MirOS: src/bin/mksh/sh.h,v 1.196 2008/03/23 20:55:18 tg Exp $"
-#define MKSH_VERSION "R33 2008/03/05"
+#define MKSH_SH_H_ID "$MirOS: src/bin/mksh/sh.h,v 1.197 2008/03/23 22:09:59 tg Exp $"
+#define MKSH_VERSION "R33 2008/03/23"
 
 #if HAVE_SYS_PARAM_H
 #include <sys/param.h>