diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
index cd396c8..cdd8b6c 100644
--- a/Lib/test/test_dict.py
+++ b/Lib/test/test_dict.py
@@ -879,6 +879,16 @@
         values = list(it) + [drop]
         self.assertEqual(sorted(values), sorted(list(data.values())))
 
+    def test_instance_dict_getattr_str_subclass(self):
+        class Foo:
+            def __init__(self, msg):
+                self.msg = msg
+        f = Foo('123')
+        class _str(str):
+            pass
+        self.assertEqual(f.msg, getattr(f, _str('msg')))
+        self.assertEqual(f.msg, f.__dict__[_str('msg')])
+
 from test import mapping_tests
 
 class GeneralMappingTests(mapping_tests.BasicTestMappingProtocol):