diff --git a/lib/krb5/kerberos.8 b/lib/krb5/kerberos.8
index 58bee1d5e..68e8e2ba5 100644
--- a/lib/krb5/kerberos.8
+++ b/lib/krb5/kerberos.8
@@ -94,9 +94,12 @@ filesystem.
 The problems with version 4 are that it has many limitations, the code
 was not too well written (since it had been developed over a long
 time), and it has a number of known security problems. To resolve many
-of these issues work on version five started, and resulted in IETF
-RFC1510 in 1993. Since then much work has been put into the further
-development, and a new RFC will hopefully appear soon.
+of these issues work on version five started, and resulted in IETF RFC
+1510 in 1993. IETF RFC 1510 was updated in 2005 with IETF RFC 4120,
+also known as Kerberos clarifications. With the arrival of IETF RFC
+4120, the work on adding extensibility and internationalization have
+started (Kerberos extensions), and a new RFC will hopefully appear
+soon.
 .Pp
 This manual page is part of the
 .Nm Heimdal