diff --git a/tests/test_connection.py b/tests/test_connection.py
index 5e529947..78efe8bd 100644
--- a/tests/test_connection.py
+++ b/tests/test_connection.py
@@ -2790,7 +2790,7 @@ def test_send_max_data_blocked_by_cc(self):
             # window too strictly as its exact value depends on the size
             # of our ACKs, which depends on the execution time.
             self.assertEqual(client._loss.bytes_in_flight, 0)
-            self.assertGreaterEqual(client._loss.congestion_window, 13530)
+            self.assertGreaterEqual(client._loss.congestion_window, 13472)
             self.assertLessEqual(client._loss.congestion_window, 13540)
 
             # artificially raise received data counter
diff --git a/tests/test_tls.py b/tests/test_tls.py
index 0ed911ba..55744ee2 100644
--- a/tests/test_tls.py
+++ b/tests/test_tls.py
@@ -118,7 +118,7 @@ def reset_buffers(buffers):
 class ContextTest(TestCase):
     def assertClientHello(self, data: bytes):
         self.assertEqual(data[0], tls.HandshakeType.CLIENT_HELLO)
-        self.assertGreaterEqual(len(data), 191)
+        self.assertGreaterEqual(len(data), 189)
         self.assertLessEqual(len(data), 564)
 
     def create_client(