diff --git a/vitest.cron.config.ts b/vitest.cron.config.ts
index 46b69ad6329..eab0e44f557 100644
--- a/vitest.cron.config.ts
+++ b/vitest.cron.config.ts
@@ -1,12 +1,22 @@
 import { createScopedVitestConfig } from "./vitest.scoped-config.ts";
 
 export function createCronVitestConfig(env?: Record<string, string | undefined>) {
-  return createScopedVitestConfig(["src/cron/**/*.test.ts"], {
+  const config = createScopedVitestConfig(["src/cron/**/*.test.ts"], {
     dir: "src",
     env,
     name: "cron",
     passWithNoTests: true,
   });
+  config.test = {
+    ...config.test,
+    maxWorkers: 1,
+    fileParallelism: false,
+    sequence: {
+      ...config.test?.sequence,
+      groupOrder: 1,
+    },
+  };
+  return config;
 }
 
 export default createCronVitestConfig();
diff --git a/vitest.project-shard-config.ts b/vitest.project-shard-config.ts
index 8fba77cbdd3..852be84d101 100644
--- a/vitest.project-shard-config.ts
+++ b/vitest.project-shard-config.ts
@@ -2,6 +2,10 @@ import { defineConfig } from "vitest/config";
 import { sharedVitestConfig } from "./vitest.shared.config.ts";
 
 export function createProjectShardVitestConfig(projects: readonly string[]) {
+  const maxWorkers = sharedVitestConfig.test.maxWorkers;
+  if (!process.env.OPENCLAW_VITEST_MAX_WORKERS && typeof maxWorkers === "number") {
+    process.env.OPENCLAW_VITEST_MAX_WORKERS = String(maxWorkers);
+  }
   return defineConfig({
     ...sharedVitestConfig,
     test: {