diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index a3c0843..ed10ed7 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -32,6 +32,8 @@
         self.assertRaises(TypeError, ctor, arg, quoting=None)
         self.assertRaises(TypeError, ctor, arg, 
                           quoting=csv.QUOTE_ALL, quotechar='')
+        self.assertRaises(TypeError, ctor, arg, 
+                          quoting=csv.QUOTE_ALL, quotechar=None)
 
     def test_reader_arg_valid(self):
         self._test_arg_valid(csv.reader, [])