diff --git a/scripts/ci-workflow.spec.ts b/scripts/ci-workflow.spec.ts
index d5c135c398..b5497b0e9e 100644
--- a/scripts/ci-workflow.spec.ts
+++ b/scripts/ci-workflow.spec.ts
@@ -288,6 +288,7 @@ describe('Python release workflows', () => {
     }
 
     expect(dispatch.inputs.publish).toMatchObject({ type: 'boolean', default: false })
+    if (!isRecord(workflow.on)) throw new TypeError('python-release workflow must define on')
     expect(Object.keys(workflow.on)).toEqual(['workflow_dispatch'])
     expect(build).toMatchObject({
       if: "github.event_name == 'workflow_dispatch'",