diff --git a/tests/fixtures/README.md b/tests/fixtures/README.md
index 603cfb2..8ec6bb3 100644
--- a/tests/fixtures/README.md
+++ b/tests/fixtures/README.md
@@ -68,6 +68,16 @@ removed before production firmware was built and flashed.
   maximum; cumulative error is 152 us over 25.75 seconds. This records bounded
   BLE scheduling jitter without rate drift and requires timestamp-derived `dt`
   in future fusion work.
+- `ble_mtu_race_4bf00eb.trk` — SHA-256
+  `4a231b54a3c7320fd69cac869b830e94aca8f704f946881b9cdfd21991bfa41f`.
+  This exact-commit stress capture followed six rapid subscribe, first-fragment,
+  and disconnect cycles aimed at the MTU lookup race. Telemetry remained live
+  afterward: the capture contains 1,848 CRC-valid samples with zero packet gaps,
+  resets, send failures, or invalid ACKs, while status records exactly six
+  disconnects and six replays. The test deliberately withheld application ACKs
+  beyond the 10.24-second queue window, so sequences 1,024 through 4,021 were
+  intentionally lost; the single 2,998-sample gap, matching queue-overflow total,
+  demonstrates bounded buffer exhaustion rather than a suspended output task.
 
 `tests/test_trikke_protocol.py` verifies the hashes, parses the captures in
 fragmented chunks, and asserts these signatures so the hardware evidence remains
diff --git a/tests/fixtures/ble_mtu_race_4bf00eb.trk b/tests/fixtures/ble_mtu_race_4bf00eb.trk
new file mode 100644
index 0000000..b74bad9
Binary files /dev/null and b/tests/fixtures/ble_mtu_race_4bf00eb.trk differ
diff --git a/tests/test_trikke_protocol.py b/tests/test_trikke_protocol.py
index cd0fbe7..d27cd6e 100644
--- a/tests/test_trikke_protocol.py
+++ b/tests/test_trikke_protocol.py
@@ -309,6 +309,24 @@ class ProtocolContractTest(unittest.TestCase):
                     "transport_invalid_ack_count": 0,
                 },
             },
+            "ble_mtu_race_4bf00eb.trk": {
+                "sha256": "4a231b54a3c7320fd69cac869b830e94aca8f704f946881b9cdfd21991bfa41f",
+                "sample_count": 1848,
+                "first_sequence": 0,
+                "last_sequence": 4845,
+                "max_dropped": 2998,
+                "timing_anomalies": 412,
+                "gaps": [(1023, 4022, 29_990_016)],
+                "final_status": {
+                    "sensor_read_failure_count": 0,
+                    "queue_overflow_count": 2998,
+                    "transport_begin_retry_count": 2471,
+                    "transport_disconnect_count": 6,
+                    "transport_send_failure_count": 0,
+                    "transport_replay_count": 6,
+                    "transport_invalid_ack_count": 0,
+                },
+            },
         }
 
         for name, contract in expected.items():