Issue #15535: Fix pickling of named tuples.
diff --git a/Lib/collections.py b/Lib/collections.py
index eb20243..33aedd9 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -281,6 +281,10 @@
         'Return self as a plain tuple.  Used by copy and pickle.'
         return tuple(self)
 
+    def __getstate__(self):
+        'Exclude the OrderedDict from pickling'
+        return None
+
 {field_defs}
 '''
 
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index b2a5f05..c18256b 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -272,6 +272,7 @@
                 q = loads(dumps(p, protocol))
                 self.assertEqual(p, q)
                 self.assertEqual(p._fields, q._fields)
+                self.assertNotIn(b'OrderedDict', dumps(p, protocol))
 
     def test_copy(self):
         p = TestNT(x=10, y=20, z=30)