diff --git a/appl/telnet/libtelnet/kerberos.c b/appl/telnet/libtelnet/kerberos.c
index 0e3737c59..67c9933fe 100644
--- a/appl/telnet/libtelnet/kerberos.c
+++ b/appl/telnet/libtelnet/kerberos.c
@@ -320,7 +320,7 @@ kerberos4_is(Authenticator *ap, unsigned char *data, int cnt)
 		      krb_unparse_name_long(adat.pname, 
 					    adat.pinst, 
 					    adat.prealm), 
-		      UserNameRequested);
+		      UserNameRequested ? UserNameRequested : "<nobody>");
 	    if (msg == NULL)
 		Data(ap, KRB_REJECT, NULL, 0);
 	    else {