diff --git a/cli/src/test/setup.ts b/cli/src/test/setup.ts
index 2f55a21f..2417037d 100644
--- a/cli/src/test/setup.ts
+++ b/cli/src/test/setup.ts
@@ -25,5 +25,8 @@ process.env.HAPI_API_URL = `http://127.0.0.1:${config.port}`
 process.env.CLI_API_TOKEN = config.token
 process.env.HAPI_HOME = config.tmpHome
 process.env.HAPI_BUN_EXEC = config.bunExec
+// The stress test starts 20 real CLI children. On slower/loaded machines their
+// session webhooks can take longer than the production control-client default.
+process.env.HAPI_RUNNER_HTTP_TIMEOUT ??= '60000'
 // Keep heartbeat short so the version-mismatch test doesn't need to wait 60s
 process.env.HAPI_RUNNER_HEARTBEAT_INTERVAL ??= '30000'