diff --git a/src/commands/openclawcode.test.ts b/src/commands/openclawcode.test.ts
index 618044fe31..dfe1ba657c 100644
--- a/src/commands/openclawcode.test.ts
+++ b/src/commands/openclawcode.test.ts
@@ -777,7 +777,7 @@ describe("openclawCodeRunCommand", () => {
     expect(payload.runAgeSeconds).toBeNull();
   });
 
-  it("prints runHasUpdatedAt as false when the workflow update signal is present but empty", async () => {
+  it("prints runHasUpdatedAt as false and runUpdatedAt as null when the workflow update signal is present but empty", async () => {
     mocks.runIssueWorkflow.mockResolvedValue(
       createRun({
         updatedAt: [] as unknown as WorkflowRun["updatedAt"],
@@ -787,7 +787,7 @@ describe("openclawCodeRunCommand", () => {
     await openclawCodeRunCommand({ issue: "2", repoRoot: "/repo", json: true }, runtime);
 
     const payload = JSON.parse(runtime.log.mock.calls[0]?.[0] ?? "null");
-    expect(payload.runUpdatedAt).toEqual([]);
+    expect(payload.runUpdatedAt).toBeNull();
     expect(payload.runHasUpdatedAt).toBe(false);
     expect(payload.runAgeSeconds).toBeNull();
   });
diff --git a/src/commands/openclawcode.ts b/src/commands/openclawcode.ts
index 70999dfed2..6f654049d5 100644
--- a/src/commands/openclawcode.ts
+++ b/src/commands/openclawcode.ts
@@ -1984,7 +1984,7 @@ function toWorkflowRunJson(run: WorkflowRun) {
     ...run,
     contractVersion: OPENCLAWCODE_RUN_JSON_CONTRACT_VERSION,
     runCreatedAt: run.createdAt ?? null,
-    runUpdatedAt: run.updatedAt ?? null,
+    runUpdatedAt: typeof run.updatedAt === "string" ? run.updatedAt : null,
     runHasUpdatedAt,
     runAgeSeconds: resolveElapsedSeconds(run.createdAt, run.updatedAt),
     issueNumber: run.issue.number ?? null,