1 files changed, 8 insertions, 0 deletions
diff --git a/Lib/test/test_augassign.py b/Lib/test/test_augassign.py
index 5093e9d..5930d9e 100644
--- a/Lib/test/test_augassign.py
+++ b/Lib/test/test_augassign.py
@@ -83,6 +83,10 @@ class AugAssignTest(unittest.TestCase):
             def __iadd__(self, val):
                 return aug_test3(self.val + val)
 
+        class aug_test4(aug_test3):
+            """Blocks inheritance, and fallback to __add__"""
+            __iadd__ = None
+
         x = aug_test(1)
         y = x
         x += 10
@@ -106,6 +110,10 @@ class AugAssignTest(unittest.TestCase):
         self.assertTrue(y is not x)
         self.assertEqual(x.val, 13)
 
+        x = aug_test4(4)
+        with self.assertRaises(TypeError):
+            x += 10
+
 
     def testCustomMethods2(test_self):
         output = []