diff --git a/lib/libc/sys/swapon.3 b/lib/libc/sys/swapon.3
index 5f152ccb9449..24bb27d08a0f 100644
--- a/lib/libc/sys/swapon.3
+++ b/lib/libc/sys/swapon.3
@@ -1,3 +1,5 @@
+.\"	$NetBSD: swapon.3,v 1.2 1998/02/28 13:58:39 enami Exp $
+.\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
 .\"
@@ -32,7 +34,7 @@
 .\"     @(#)swapon.2	8.1 (Berkeley) 6/4/93
 .\"
 .Dd June 4, 1993
-.Dt SWAPON 2
+.Dt SWAPON 3
 .Os BSD 4
 .Sh NAME
 .Nm swapon
@@ -42,6 +44,13 @@
 .Ft int
 .Fn swapon "const char *special"
 .Sh DESCRIPTION
+.Bf -symbolic
+.\" This interface is available from the compatibility library, libcompat and
+This interface is provided for compatibility only and
+has been obsoleted by 
+.Xr swapctl 2 .
+.Ef
+.Pp
 .Fn Swapon
 makes the block device 
 .Fa special
@@ -62,11 +71,12 @@ succeeds unless:
 .Bl -tag -width ENAMETOOLONG
 .It Bq Er ENOTDIR
 A component of the path prefix is not a directory.
-.It Bq Er EINVAL
-The pathname contains a character with the high-order bit set.
 .It Bq Er ENAMETOOLONG
-A component of a pathname exceeded 255 characters,
-or an entire path name exceeded 1023 characters.
+A component of a pathname exceeded 
+.Dv {NAME_MAX}
+characters, or an entire path name exceeded 
+.Dv {PATH_MAX}
+characters.
 .It Bq Er ENOENT
 The named device does not exist.
 .It Bq Er EACCES
@@ -108,6 +118,8 @@ dismounted.
 This call will be upgraded in future versions of the system.
 .Sh HISTORY
 The
-.Nm
+.Fn swapon
 function call appeared in
-.Bx 4.0 .
+.Bx 4.0
+and was removed
+.Nx 1.3