diff --git a/server/src/__tests__/heartbeat-workspace-busy.test.ts b/server/src/__tests__/heartbeat-workspace-busy.test.ts
index 15ab976c55..1b6ec47da7 100644
--- a/server/src/__tests__/heartbeat-workspace-busy.test.ts
+++ b/server/src/__tests__/heartbeat-workspace-busy.test.ts
@@ -176,6 +176,29 @@ describeEmbeddedPostgres("shared-workspace run serialization", () => {
     return await heartbeat.getRun(runId);
   }
 
+  // A deferral does two writes in order: first it cancels the original run,
+  // then it inserts the scheduled-retry row. waitForRunToLeaveActiveStates
+  // returns after the first write, so a read of the retry row can land before
+  // the second write and find nothing. Poll until the retry row exists so the
+  // retry-row assertions never observe the gap between the two writes.
+  async function waitForRetryRun(originalRunId: string, timeoutMs = 10_000) {
+    const deadline = Date.now() + timeoutMs;
+    while (Date.now() < deadline) {
+      const retryRun = await db
+        .select()
+        .from(heartbeatRuns)
+        .where(eq(heartbeatRuns.retryOfRunId, originalRunId))
+        .then((rows) => rows[0] ?? null);
+      if (retryRun) return retryRun;
+      await new Promise((resolve) => setTimeout(resolve, 50));
+    }
+    return await db
+      .select()
+      .from(heartbeatRuns)
+      .where(eq(heartbeatRuns.retryOfRunId, originalRunId))
+      .then((rows) => rows[0] ?? null);
+  }
+
   interface WorkspaceFixture {
     companyId: string;
     projectId: string;
@@ -491,11 +514,7 @@ describeEmbeddedPostgres("shared-workspace run serialization", () => {
     // The deferred run's adapter never executed — the whole point of the gate.
     expect(executedRunIds).not.toContain(run!.id);
 
-    const retryRun = await db
-      .select()
-      .from(heartbeatRuns)
-      .where(eq(heartbeatRuns.retryOfRunId, run!.id))
-      .then((rows) => rows[0] ?? null);
+    const retryRun = await waitForRetryRun(run!.id);
     expect(retryRun).toMatchObject({
       status: "scheduled_retry",
       scheduledRetryAttempt: 1,
@@ -560,11 +579,7 @@ describeEmbeddedPostgres("shared-workspace run serialization", () => {
     const deferred = await waitForRunToLeaveActiveStates(run!.id);
     expect(deferred?.status).toBe("cancelled");
 
-    const retryRun = await db
-      .select()
-      .from(heartbeatRuns)
-      .where(eq(heartbeatRuns.retryOfRunId, run!.id))
-      .then((rows) => rows[0] ?? null);
+    const retryRun = await waitForRetryRun(run!.id);
     expect(retryRun?.status).toBe("scheduled_retry");
 
     // Holder finishes; the due retry promotes, queues, and executes.
@@ -606,11 +621,7 @@ describeEmbeddedPostgres("shared-workspace run serialization", () => {
     expect(deferred?.errorCode).toBe(WORKSPACE_BUSY_ERROR_CODE);
     expect(executedRunIds).not.toContain(run!.id);
 
-    const retryRun = await db
-      .select()
-      .from(heartbeatRuns)
-      .where(eq(heartbeatRuns.retryOfRunId, run!.id))
-      .then((rows) => rows[0] ?? null);
+    const retryRun = await waitForRetryRun(run!.id);
     expect(retryRun).toMatchObject({
       status: "scheduled_retry",
       scheduledRetryReason: WORKSPACE_BUSY_RETRY_REASON,
@@ -658,11 +669,7 @@ describeEmbeddedPostgres("shared-workspace run serialization", () => {
     const deferred = await waitForRunToLeaveActiveStates(run!.id);
     expect(deferred?.status).toBe("cancelled");
 
-    const retryRun = await db
-      .select()
-      .from(heartbeatRuns)
-      .where(eq(heartbeatRuns.retryOfRunId, run!.id))
-      .then((rows) => rows[0] ?? null);
+    const retryRun = await waitForRetryRun(run!.id);
     expect(retryRun?.status).toBe("scheduled_retry");
     expect(
       (retryRun?.contextSnapshot as Record<string, unknown> | null)?.workspaceBusyDeferredWhileAssignee,
@@ -849,11 +856,7 @@ describeEmbeddedPostgres("shared-workspace run serialization", () => {
     expect(finishedRun?.errorCode).toBe(WORKSPACE_BUSY_ERROR_CODE);
     expect(executedRunIds).not.toContain(retryRunId);
 
-    const nextRetry = await db
-      .select()
-      .from(heartbeatRuns)
-      .where(eq(heartbeatRuns.retryOfRunId, retryRunId))
-      .then((rows) => rows[0] ?? null);
+    const nextRetry = await waitForRetryRun(retryRunId);
     expect(nextRetry).toMatchObject({
       status: "scheduled_retry",
       scheduledRetryAttempt: priorAttempts + 1,