diff --git a/tests/hermes_cli/test_local_quickstart.py b/tests/hermes_cli/test_local_quickstart.py
index aa82247cc4..b18c28c490 100644
--- a/tests/hermes_cli/test_local_quickstart.py
+++ b/tests/hermes_cli/test_local_quickstart.py
@@ -57,6 +57,14 @@ def test_quickstart_runs_all_three_legs(client, monkeypatch, tmp_path):
     Each leg is asserted by its observable call, in order."""
     calls: list[str] = []
 
+    # Supply the same supported backend to preflight and the stubbed install;
+    # host auto-detection may select CUDA without a published Linux archive.
+    from hermes_cli.config import load_config, save_config
+
+    config = load_config()
+    config.setdefault("local_runtime", {})["backend"] = "cpu"
+    save_config(config)
+
     # Leg 1: no runtime installed yet; install is the stubbed binaries call.
     monkeypatch.setattr(
         "hermes_cli.local_runtime.binaries.installed_tags", lambda: [])