--- src/usr.bin/biff/biff.c	2005/01/11 19:36:09	1.4
+++ src/usr.bin/biff/biff.c	2007/09/16 00:59:59	1.5
@@ -64,7 +64,9 @@ main(int argc, char **argv)
 	argc -= optind;
 	argv += optind;
 
-	if ((name = ttyname(STDERR_FILENO)) == NULL)
+	if ((name = ttyname(STDIN_FILENO)) == NULL &&
+	    (name = ttyname(STDOUT_FILENO)) == NULL &&
+	    (name = ttyname(STDERR_FILENO)) == NULL)
 		err(2, "unknown tty");
 
 	if (stat(name, &sb))