diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
index 008b15e8063a..5dc0e3e5910f 100644
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -14,6 +14,8 @@
 # The file is partitioned: OLD_FILES first, then OLD_LIBS and OLD_DIRS last.
 #
 
+# 20100114: removal of ttyslot(3)
+OLD_FILES+=usr/share/man/man3/ttyslot.3.gz
 # 20100113: remove utmp.h, replace it by utmpx.h
 OLD_FILES+=usr/share/man/man3/login.3.gz
 OLD_FILES+=usr/share/man/man3/logout.3.gz
diff --git a/include/unistd.h b/include/unistd.h
index b4b7516bc6ac..5ac79718de90 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -574,7 +574,6 @@ int	 swapon(const char *);
 int	 swapoff(const char *);
 int	 syscall(int, ...);
 off_t	 __syscall(quad_t, ...);
-int	 ttyslot(void);
 int	 undelete(const char *);
 int	 unwhiteout(const char *);
 void	*valloc(size_t);			/* obsoleted by malloc() */
diff --git a/lib/libc/gen/Symbol.map b/lib/libc/gen/Symbol.map
index 534c81acffd4..42404bcc277c 100644
--- a/lib/libc/gen/Symbol.map
+++ b/lib/libc/gen/Symbol.map
@@ -272,7 +272,6 @@ FBSD_1.0 {
 	openlog;
 	closelog;
 	setlogmask;
-	ttyslot;
 	ttyname_r;
 	ttyname;
 	timezone;
diff --git a/lib/libc/gen/ttyname.3 b/lib/libc/gen/ttyname.3
index c7b8cbcd3c84..e58383331eac 100644
--- a/lib/libc/gen/ttyname.3
+++ b/lib/libc/gen/ttyname.3
@@ -34,8 +34,7 @@
 .Sh NAME
 .Nm ttyname ,
 .Nm ttyname_r ,
-.Nm isatty ,
-.Nm ttyslot
+.Nm isatty
 .Nd get name of associated terminal (tty) from file descriptor
 .Sh LIBRARY
 .Lb libc
@@ -47,8 +46,6 @@
 .Fn ttyname_r "int fd" "char *buf" "size_t len"
 .Ft int
 .Fn isatty "int fd"
-.Ft int
-.Fn ttyslot void
 .Sh DESCRIPTION
 These functions operate on the system file descriptors for terminal
 type devices.
@@ -89,13 +86,6 @@ The
 .Fn ttyname_r
 function
 takes a buffer and length as arguments to avoid this problem.
-.Pp
-The
-.Fn ttyslot
-function
-fetches the current process' control terminal number from the
-.Xr ttys 5
-file entry.
 .Sh RETURN VALUES
 The
 .Fn ttyname
@@ -110,12 +100,6 @@ The
 .Fn ttyname_r
 function returns 0 if successful.
 Otherwise an error number is returned.
-.Pp
-The
-.Fn ttyslot
-function
-returns the unit number of the device file if found; otherwise
-the value zero is returned.
 .Sh FILES
 .Bl -tag -width ".Pa /etc/ttys" -compact
 .It Pa /dev/\(**
@@ -142,10 +126,9 @@ is smaller than the length of the string to be returned.
 .Xr ttys 5
 .Sh HISTORY
 The
-.Fn isatty ,
-.Fn ttyname ,
+.Fn isatty
 and
-.Fn ttyslot
+.Fn ttyname
 functions
 appeared in
 .At v7 .
diff --git a/lib/libc/gen/ttyslot.c b/lib/libc/gen/ttyslot.c
index 31cc15621f33..b2fac7c0aef4 100644
--- a/lib/libc/gen/ttyslot.c
+++ b/lib/libc/gen/ttyslot.c
@@ -40,7 +40,7 @@ __FBSDID("$FreeBSD$");
 #include <unistd.h>
 
 int
-ttyslot()
+__ttyslot(void)
 {
 	struct ttyent *ttyp;
 	int slot;
@@ -63,3 +63,5 @@ ttyslot()
 	endttyent();
 	return(0);
 }
+
+__sym_compat(ttyslot, __ttyslot, FBSD_1.0);
diff --git a/libexec/getty/ttys.5 b/libexec/getty/ttys.5
index cf2423a9320d..18151c9855fe 100644
--- a/libexec/getty/ttys.5
+++ b/libexec/getty/ttys.5
@@ -158,7 +158,6 @@ ttyp1	none	network	off	group=pty
 .Sh SEE ALSO
 .Xr login 1 ,
 .Xr getttyent 3 ,
-.Xr ttyslot 3 ,
 .Xr gettytab 5 ,
 .Xr login.conf 5 ,
 .Xr termcap 5 ,