diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index 232bffc..7f5f08b 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -2,6 +2,8 @@
 import unittest
 import struct
 import warnings
+warnings.filterwarnings("ignore", "struct integer overflow masking is deprecated",
+                        DeprecationWarning)
 
 from functools import wraps
 from test.test_support import TestFailed, verbose, run_unittest
@@ -461,6 +463,11 @@
                 self.check_float_coerce(endian + fmt, 1.0)
                 self.check_float_coerce(endian + fmt, 1.5)
 
+    def test_issue4228(self):
+        # Packing a long may yield either 32 or 64 bits
+        x = struct.pack('L', -1)[:4]
+        self.assertEqual(x, '\xff'*4)
+
     def test_unpack_from(self):
         test_string = 'abcd01234'
         fmt = '4s'