From 9c297e43bf5cdf939ee165a2e177794dc352fa17 Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Sat, 19 Dec 2015 22:49:29 +0200
Subject: [PATCH] Use correct PyGC_Head size in tests for issue #25421.

---
 Lib/test/test_sys.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 4f1577d65d..5a37537acd 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -1115,7 +1115,7 @@ class SizeofTest(unittest.TestCase):
     def check_slots(self, obj, base, extra):
         expected = sys.getsizeof(base) + struct.calcsize(extra)
         if gc.is_tracked(obj) and not gc.is_tracked(base):
-            expected += struct.calcsize('2Pn')  # PyGC_Head
+            expected += self.gc_headsize
         self.assertEqual(sys.getsizeof(obj), expected)
 
     def test_slots(self):
-- 
2.49.0