diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 42462f4..1e1bdbe 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -507,7 +507,7 @@
         sentinel = ["sentinel"]
         self.assertIs(sys.getsizeof(InvalidSizeof(), sentinel), sentinel)
 
-        class OverflowSizeof(int):
+        class OverflowSizeof(long):
             def __sizeof__(self):
                 return int(self)
         self.assertEqual(sys.getsizeof(OverflowSizeof(sys.maxsize)),