diff --git a/tests/unit/test_server.py b/tests/unit/test_server.py
index 1f474f3..7530acb 100644
--- a/tests/unit/test_server.py
+++ b/tests/unit/test_server.py
@@ -55,6 +55,11 @@ class TestHealthEndpoint:
         """Test liveness endpoint returns quickly."""
         import time
 
+        # Warm up once so the timed call measures steady-state latency rather
+        # than one-time TestClient/route initialization (which can exceed the
+        # threshold on slow CI runners and cause flaky failures).
+        client.get("/health/live")
+
         start = time.time()
         response = client.get("/health/live")
         duration = time.time() - start