Fix 32-bit-ism in protocol seqno rollover test from Terrapin fix

Fixes #2353

1 files changed, 6 insertions, 3 deletions

diff --git a/tests/test_transport.py b/tests/test_transport.py
index 67e2eb45..59f871b8 100644
--- a/tests/test_transport.py
+++ b/tests/test_transport.py
@@ -1419,16 +1419,19 @@ class TestStrictKex:
             def __init__(self, *args, **kwargs):
                 super().__init__(*args, **kwargs)
                 # Induce an about-to-rollover seqno, such that it rolls over
-                # during initial kex.
+                # during initial kex. (Sequence numbers are uint32, so we need
+                # the largest possible 32bit integer such that incrementing it
+                # will roll over to 0.)
+                last_seq = 2**32 - 1
                 setattr(
                     self.packetizer,
                     "_Packetizer__sequence_number_in",
-                    sys.maxsize,
+                    last_seq,
                 )
                 setattr(
                     self.packetizer,
                     "_Packetizer__sequence_number_out",
-                    sys.maxsize,
+                    last_seq,
                 )
 
         with raises(