diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b486e5df30..bb9f01026e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -504,6 +504,8 @@ jobs:
         shell: pwsh
         run: >-
           pnpm exec vitest run
+          --no-file-parallelism
+          --testTimeout 30000
           packages/shell/tool-pwsh/tests/loader.spec.ts
           packages/workflow/workflow-worker-thread/tests/workflow-worker-thread.spec.ts
           packages/workflow/tool-ralph/tests/integration.spec.ts
diff --git a/scripts/ci-workflow.spec.ts b/scripts/ci-workflow.spec.ts
index a4011ba06c..40a665d667 100644
--- a/scripts/ci-workflow.spec.ts
+++ b/scripts/ci-workflow.spec.ts
@@ -113,8 +113,11 @@ describe('CI workflow', () => {
     const nativeTestCommands = nativeTestSteps.filter((step): step is Record<string, unknown> & { run: string } => (
       isRecord(step) && typeof step.run === 'string'
     ))
-    expect(nativeTestCommands.map(step => step.run).join('\n')).toContain('tool-pwsh/tests/loader.spec.ts')
-    expect(nativeTestCommands.map(step => step.run).join('\n')).toContain('workflow-worker-thread.spec.ts')
+    const nativeTestCommand = nativeTestCommands.map(step => step.run).join('\n')
+    expect(nativeTestCommand).toContain('--no-file-parallelism')
+    expect(nativeTestCommand).toContain('--testTimeout 30000')
+    expect(nativeTestCommand).toContain('tool-pwsh/tests/loader.spec.ts')
+    expect(nativeTestCommand).toContain('workflow-worker-thread.spec.ts')
 
     // windows-observational is non-blocking.
     expect(windowsObservational.name).toBe('windows node 24 / observational')