diff --git a/tests/unit/vertexai/genai/replays/test_ae_session_events_append.py b/tests/unit/vertexai/genai/replays/test_ae_session_events_append.py
index 3cbef0d47a..4319a78533 100644
--- a/tests/unit/vertexai/genai/replays/test_ae_session_events_append.py
+++ b/tests/unit/vertexai/genai/replays/test_ae_session_events_append.py
@@ -25,7 +25,7 @@ def test_append_session_event(client):
         name="reasoningEngines/2886612747586371584/sessions/6922431337672474624",
         author="test-user-123",
         invocation_id="test-invocation-id",
-        timestamp=datetime.datetime.fromtimestamp(1234567890, tz=datetime.timezone.utc),
+        timestamp=datetime.datetime.fromtimestamp(1234567860, tz=datetime.timezone.utc),
     )
     assert isinstance(session_event, types.AppendAgentEngineSessionEventResponse)