diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 486b37cd9e0..68dc2b1afc1 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -72,8 +72,8 @@ def test_same_as_binascii_crc32(self):
 # Issue #10276 - check that inputs >=4GB are handled correctly.
 class ChecksumBigBufferTestCase(unittest.TestCase):
 
-    @bigmemtest(size=_4G + 4, memuse=1)
-    def test_big_buffer(self,size):
+    @bigmemtest(size=_4G + 4, memuse=1, dry_run=False)
+    def test_big_buffer(self, size):
         data = b"nyan" * (_1G + 1)
         self.assertEqual(zlib.crc32(data), 1044521549)
         self.assertEqual(zlib.adler32(data), 2256789997)