--- libaitio/src/pty.c	2011/09/28 14:36:31	1.1.2.9
+++ libaitio/src/pty.c	2011/10/31 13:53:51	1.2
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@openbsd-bg.org>
 *
 * $Author: misho $
-* $Id: pty.c,v 1.1.2.9 2011/09/28 14:36:31 misho Exp $
+* $Id: pty.c,v 1.2 2011/10/31 13:53:51 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -90,8 +90,10 @@ ioFreePTY(int ptyfd, const char *ttyname)
 
 	if (ptyfd != -1)
 		close(ptyfd);
-	chown(ttyname, (uid_t) 0, (gid_t) 0);
-	chmod(ttyname, (mode_t) 0666);
+	if (ttyname) {
+		chown(ttyname, (uid_t) 0, (gid_t) 0);
+		chmod(ttyname, (mode_t) 0666);
+	}
 }
 
 /*