diff --git a/tests/listener_contract.py b/tests/listener_contract.py
--- a/tests/listener_contract.py
+++ b/tests/listener_contract.py
@@ -114,6 +114,14 @@
         )
         assert wait_for(process, debug_port, "/healthz") == (200, b"ok\n")
         assert request(debug_port, "/readyz") == (200, b"ok\n")
+        # Listeners now bind BEFORE storage opens (upstream's server-first
+        # startup): /readyz 200 means accepting, not serving. Wait out the
+        # startup gate — /status says "starting" and subscribe 503s until
+        # main publishes the stores — before asserting the serving contract.
+        deadline = time.time() + 30
+        while b"state            starting" in request(public_port, "/status")[1]:
+            assert time.time() < deadline, "startup gate never opened"
+            time.sleep(0.05)
         for path in ("/healthz", "/readyz", "/metrics"):
             assert request(debug_port, path, "HEAD")[0] == 200, path
             assert request(debug_port, path, "HEAD")[1] == b"", path