diff --git a/src/lib/libc/crypt/arc4random.3 b/src/lib/libc/crypt/arc4random.3
index b10115c4..1c3ddcb1 100644
--- a/src/lib/libc/crypt/arc4random.3
+++ b/src/lib/libc/crypt/arc4random.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: arc4random.3,v 1.11 1999/07/09 13:35:15 aaron Exp $
+.\" $OpenBSD: arc4random.3,v 1.12 2000/04/02 17:59:04 millert Exp $
 .\" Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
 .\" All rights reserved.
 .\"
@@ -83,3 +83,6 @@ Since
 .Pa RC4
 used to be a trade secret, the cipher is now referred to as
 .Pa ARC4 .
+.Pp
+These functions first appeared in
+.Ox 2.1 .