diff --git a/src/cron/service.read-ops-nonblocking.test.ts b/src/cron/service.read-ops-nonblocking.test.ts
index 048246cc5cb..3a649d7ce90 100644
--- a/src/cron/service.read-ops-nonblocking.test.ts
+++ b/src/cron/service.read-ops-nonblocking.test.ts
@@ -16,6 +16,21 @@ async function makeStorePath() {
   return {
     storePath: path.join(dir, "cron", "jobs.json"),
     cleanup: async () => {
+      // On macOS, teardown can race with trailing async fs writes and leave
+      // transient ENOTEMPTY errors. Retry briefly for stability.
+      for (let i = 0; i < 10; i += 1) {
+        try {
+          await fs.rm(dir, { recursive: true, force: true });
+          return;
+        } catch (err) {
+          const code = (err as NodeJS.ErrnoException).code;
+          if (code !== "ENOTEMPTY") {
+            throw err;
+          }
+          // eslint-disable-next-line no-await-in-loop
+          await new Promise<void>((resolve) => setTimeout(resolve, 10));
+        }
+      }
       await fs.rm(dir, { recursive: true, force: true });
     },
   };
@@ -23,24 +38,35 @@ async function makeStorePath() {
 
 describe("CronService read ops while job is running", () => {
   it("keeps list and status responsive during a long isolated run", async () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2025-12-13T00:00:00.000Z"));
     const store = await makeStorePath();
     const enqueueSystemEvent = vi.fn();
     const requestHeartbeatNow = vi.fn();
+    let resolveFinished: (() => void) | undefined;
+    const finished = new Promise<void>((resolve) => {
+      resolveFinished = resolve;
+    });
 
     let resolveRun:
       | ((value: { status: "ok" | "error" | "skipped"; summary?: string; error?: string }) => void)
       | undefined;
 
-    const runIsolatedAgentJob = vi.fn(
-      async () =>
-        await new Promise<{
-          status: "ok" | "error" | "skipped";
-          summary?: string;
-          error?: string;
-        }>((resolve) => {
-          resolveRun = resolve;
-        }),
-    );
+    let resolveRunStarted: (() => void) | undefined;
+    const runStarted = new Promise<void>((resolve) => {
+      resolveRunStarted = resolve;
+    });
+
+    const runIsolatedAgentJob = vi.fn(async () => {
+      resolveRunStarted?.();
+      return await new Promise<{
+        status: "ok" | "error" | "skipped";
+        summary?: string;
+        error?: string;
+      }>((resolve) => {
+        resolveRun = resolve;
+      });
+    });
 
     const cron = new CronService({
       storePath: store.storePath,
@@ -49,70 +75,67 @@ describe("CronService read ops while job is running", () => {
       enqueueSystemEvent,
       requestHeartbeatNow,
       runIsolatedAgentJob,
+      onEvent: (evt) => {
+        if (evt.action === "finished" && evt.status === "ok") {
+          resolveFinished?.();
+        }
+      },
     });
 
-    const timeout = async <T>(promise: Promise<T>, ms: number): Promise<T> => {
-      let t: NodeJS.Timeout;
-      const timeoutPromise = new Promise<never>((_, reject) => {
-        t = setTimeout(() => reject(new Error("timeout")), ms);
-      });
-      return await Promise.race([promise.finally(() => clearTimeout(t!)), timeoutPromise]);
-    };
-
     try {
       await cron.start();
 
-      // Schedule the job in the past so the cron timer fires immediately.
+      // Schedule the job a second in the future; then jump time to trigger the tick.
       await cron.add({
         name: "slow isolated",
         enabled: true,
         deleteAfterRun: false,
-        schedule: { kind: "at", at: new Date(Date.now() - 1).toISOString() },
+        schedule: {
+          kind: "at",
+          at: new Date("2025-12-13T00:00:01.000Z").toISOString(),
+        },
         sessionTarget: "isolated",
         wakeMode: "next-heartbeat",
         payload: { kind: "agentTurn", message: "long task" },
         delivery: { mode: "none" },
       });
 
-      // Let the scheduler tick and start the job.
-      await timeout(
-        (async () => {
-          for (;;) {
-            if (runIsolatedAgentJob.mock.calls.length > 0) {
-              return;
-            }
-            await new Promise<void>((resolve) => setTimeout(resolve, 0));
-          }
-        })(),
-        2000,
-      );
+      vi.setSystemTime(new Date("2025-12-13T00:00:01.000Z"));
+      await vi.runOnlyPendingTimersAsync();
 
+      await runStarted;
       expect(runIsolatedAgentJob).toHaveBeenCalledTimes(1);
 
-      await expect(timeout(cron.list({ includeDisabled: true }), 1000)).resolves.toBeTypeOf(
-        "object",
-      );
-      await expect(timeout(cron.status(), 1000)).resolves.toBeTypeOf("object");
+      await expect(cron.list({ includeDisabled: true })).resolves.toBeTypeOf("object");
+      await expect(cron.status()).resolves.toBeTypeOf("object");
 
       const running = await cron.list({ includeDisabled: true });
       expect(running[0]?.state.runningAtMs).toBeTypeOf("number");
 
       resolveRun?.({ status: "ok", summary: "done" });
 
-      await timeout(
-        (async () => {
-          for (;;) {
-            const finished = await cron.list({ includeDisabled: true });
-            if (finished[0]?.state.lastStatus === "ok") {
-              return;
-            }
-            await new Promise<void>((resolve) => setTimeout(resolve, 0));
-          }
-        })(),
-        2000,
-      );
+      // Wait until the scheduler writes the result back to the store.
+      await finished;
+      // Ensure any trailing store writes have finished before cleanup.
+      await cron.status();
+
+      const completed = await cron.list({ includeDisabled: true });
+      expect(completed[0]?.state.lastStatus).toBe("ok");
+
+      // Ensure the scheduler loop has fully settled before deleting the store directory.
+      const internal = cron as unknown as { state?: { running?: boolean } };
+      for (let i = 0; i < 100; i += 1) {
+        if (!internal.state?.running) {
+          break;
+        }
+        // eslint-disable-next-line no-await-in-loop
+        await Promise.resolve();
+      }
+      expect(internal.state?.running).toBe(false);
     } finally {
       cron.stop();
+      vi.clearAllTimers();
+      vi.useRealTimers();
       await store.cleanup();
     }
   });
diff --git a/src/cron/service/timer.ts b/src/cron/service/timer.ts
index 08cdfad626d..674f191a875 100644
--- a/src/cron/service/timer.ts
+++ b/src/cron/service/timer.ts
@@ -144,12 +144,13 @@ export function armTimer(state: CronServiceState) {
   // Wake at least once a minute to avoid schedule drift and recover quickly
   // when the process was paused or wall-clock time jumps.
   const clampedDelay = Math.min(delay, MAX_TIMER_DELAY_MS);
-  state.timer = setTimeout(async () => {
-    try {
-      await onTimer(state);
-    } catch (err) {
+  // Intentionally avoid an `async` timer callback:
+  // Vitest's fake-timer helpers can await async callbacks, which would block
+  // tests that simulate long-running jobs. Runtime behavior is unchanged.
+  state.timer = setTimeout(() => {
+    void onTimer(state).catch((err) => {
       state.deps.log.error({ err: String(err) }, "cron: timer tick failed");
-    }
+    });
   }, clampedDelay);
   state.deps.log.debug(
     { nextAt, delayMs: clampedDelay, clamped: delay > MAX_TIMER_DELAY_MS },
@@ -172,12 +173,10 @@ export async function onTimer(state: CronServiceState) {
     if (state.timer) {
       clearTimeout(state.timer);
     }
-    state.timer = setTimeout(async () => {
-      try {
-        await onTimer(state);
-      } catch (err) {
+    state.timer = setTimeout(() => {
+      void onTimer(state).catch((err) => {
         state.deps.log.error({ err: String(err) }, "cron: timer tick failed");
-      }
+      });
     }, MAX_TIMER_DELAY_MS);
     return;
   }