diff --git a/tests/cursor_lookback_contract.py b/tests/cursor_lookback_contract.py
index 9ae14a3..ee9bd0e 100644
--- a/tests/cursor_lookback_contract.py
+++ b/tests/cursor_lookback_contract.py
@@ -66,6 +66,11 @@ def read_frame(connection, buffered):
     return payload, buffered
 
 
+# The sample archive's events are stamped in 2023, so every segment is older
+# than now-36h and the floor takes upstream's clamp branch: the MinSeq of the
+# freshest SEALED segment. The sample's third segment is left active (unsealed)
+# and startup resumes it in place, as upstream's ingest.Open does, so the floor
+# is segment 1's min_seq (2001) -- not the active segment's first seq (4001).
 if MODE == "default":
     connection, status, headers, buffered = handshake("/subscribe-v2?cursor=1")
     try:
@@ -74,7 +79,7 @@ if MODE == "default":
         body, _ = read_exact(connection, buffered, length)
         text = body.decode()
         assert "subscribe: cursor too old" in text
-        assert "cursor 1 below lookback floor 4001" in text
+        assert "cursor 1 below lookback floor 2001" in text
     finally:
         connection.close()
 
@@ -83,7 +88,7 @@ if MODE == "default":
         assert status.startswith("HTTP/1.1 101")
         payload, _ = read_frame(connection, buffered)
         event = json.loads(payload)
-        assert event["time_us"] == 1_700_000_004_001_000
+        assert event["time_us"] == 1_700_000_002_001_000
     finally:
         connection.close()
 elif MODE == "wide":