diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 7373334..f7471e5 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -588,7 +588,7 @@
         self.assertRaises(WindowsError, os.utime, support.TESTFN, 0)
 
 class TestInvalidFD(unittest.TestCase):
-    singles = ["fchdir", "dup", "fdatasync", "fstat",
+    singles = ["fchdir", "dup", "fdopen", "fdatasync", "fstat",
                "fstatvfs", "fsync", "tcgetpgrp", "ttyname"]
     #singles.append("close")
     #We omit close because it doesn'r raise an exception on some platforms