1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libc/stdlib/posix_pty.c b/src/lib/libc/stdlib/posix_pty.c
index a2025ddbb6..72b5d527cc 100644
--- a/src/lib/libc/stdlib/posix_pty.c
+++ b/src/lib/libc/stdlib/posix_pty.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: posix_pty.c,v 1.1 2012/12/03 20:08:33 millert Exp $   */
+/*      $OpenBSD: posix_pty.c,v 1.2 2015/05/11 00:42:54 guenther Exp $  */
 
 /*
  * Copyright (c) 2012 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -35,7 +35,8 @@ posix_openpt(int oflag)
         int fd, mfd = -1;
 
         /* User must specify O_RDWR in oflag. */
-        if (!(oflag & O_RDWR)) {
+        if ((oflag & O_ACCMODE) != O_RDWR ||
+            (oflag & ~(O_ACCMODE | O_NOCTTY)) != 0) {
                 errno = EINVAL;
                 return -1;
         }