diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index f8168bd19f4..6ff7f612867 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -2900,7 +2900,7 @@ class ProtocolTests(BaseTestCase):
             self.assertEqual(x.bar, 'abc')
             self.assertEqual(x.x, 1)
             self.assertEqual(x.__dict__, {'foo': 42, 'bar': 'abc'})
-            s = pickle.dumps(P)
+            s = pickle.dumps(P, proto)
             D = pickle.loads(s)
 
             class E: