diff --git a/Lib/test/test_ioctl.py b/Lib/test/test_ioctl.py
index 2b127e2..9e6d4bc 100644
--- a/Lib/test/test_ioctl.py
+++ b/Lib/test/test_ioctl.py
@@ -14,6 +14,11 @@
 except IOError:
     raise TestSkipped("Unable to open /dev/tty")
 
+try:
+    import pty
+except ImportError:
+    pty = None
+
 class IoctlTests(unittest.TestCase):
     def test_ioctl(self):
         # If this process has been put into the background, TIOCGPGRP returns
@@ -34,6 +39,30 @@
         self.assertEquals(r, 0)
         self.assert_(rpgrp in ids, "%s not in %s" % (rpgrp, ids))
 
+    def test_ioctl_signed_unsigned_code_param(self):
+        if not pty:
+            raise TestSkipped('pty module required')
+        mfd, sfd = pty.openpty()
+        try:
+            if termios.TIOCSWINSZ < 0:
+                set_winsz_opcode_maybe_neg = termios.TIOCSWINSZ
+                set_winsz_opcode_pos = termios.TIOCSWINSZ & 0xffffffffL
+            else:
+                set_winsz_opcode_pos = termios.TIOCSWINSZ
+                set_winsz_opcode_maybe_neg, = struct.unpack("i",
+                        struct.pack("I", termios.TIOCSWINSZ))
+
+            # We're just testing that these calls do not raise exceptions.
+            saved_winsz = fcntl.ioctl(mfd, termios.TIOCGWINSZ, "\0"*8)
+            our_winsz = struct.pack("HHHH",80,25,0,0)
+            # test both with a positive and potentially negative ioctl code
+            new_winsz = fcntl.ioctl(mfd, set_winsz_opcode_pos, our_winsz)
+            new_winsz = fcntl.ioctl(mfd, set_winsz_opcode_maybe_neg, our_winsz)
+            fcntl.ioctl(mfd, set_winsz_opcode_maybe_neg, saved_winsz)
+        finally:
+            os.close(mfd)
+            os.close(sfd)
+
 def test_main():
     run_unittest(IoctlTests)