diff -r 2a142141e5fd Lib/test/test_io.py
--- a/Lib/test/test_io.py	Thu Mar 08 20:58:29 2012 -0800
+++ b/Lib/test/test_io.py	Fri Mar 09 12:37:25 2012 +0000
@@ -339,6 +339,10 @@
         self.assertEqual(f.seek(0, 2), self.LARGE + 1)
         self.assertEqual(f.seek(-1, 2), self.LARGE)
         self.assertEqual(f.read(2), b"x")
+
+    def test_UnsupportedOperation_new(self):
+        ex = self.UnsupportedOperation.__new__(self.UnsupportedOperation)
+        self.assertTrue(type(ex) == self.UnsupportedOperation)
 
     def test_invalid_operations(self):
         # Try writing on a file opened in read mode and vice-versa.
diff -r 2a142141e5fd Modules/_io/_iomodule.c
--- a/Modules/_io/_iomodule.c	Thu Mar 08 20:58:29 2012 -0800
+++ b/Modules/_io/_iomodule.c	Fri Mar 09 12:37:25 2012 +0000
@@ -609,7 +609,7 @@
     /* UnsupportedOperation inherits from ValueError and IOError */
     state->unsupported_operation = PyObject_CallFunction(
         (PyObject *)&PyType_Type, "s(OO){}",
-        "UnsupportedOperation", PyExc_ValueError, PyExc_IOError);
+        "UnsupportedOperation", PyExc_IOError, PyExc_ValueError);
     if (state->unsupported_operation == NULL)
         goto fail;
     Py_INCREF(state->unsupported_operation);