diff --git a/apps/server/test/threads/thread-send-dispatch.test.ts b/apps/server/test/threads/thread-send-dispatch.test.ts
index 2eb879af1..d9a9e0282 100644
--- a/apps/server/test/threads/thread-send-dispatch.test.ts
+++ b/apps/server/test/threads/thread-send-dispatch.test.ts
@@ -1423,3 +1423,30 @@ describe("service tier execution lifecycle", () => {
     });
   });
 });
+
+describe("concurrent idle dispatch regression", () => {
+  it("retains every concurrent queue-mode send", async () => {
+    await withTestHarness(async (harness) => {
+      const { thread } = seedProviderThreadFixture({ harness, value: 3716 });
+      const results = await Promise.allSettled(
+        Array.from({ length: 4 }, (_, index) =>
+          acceptThreadSendRequest(harness.deps, {
+            thread,
+            payload: {
+              input: textInput(`concurrent message ${index}`),
+              mode: "queue-if-active",
+              model: "gpt-5",
+              permissionMode: "full",
+              reasoningLevel: "medium",
+              serviceTier: "default",
+            },
+          }),
+        ),
+      );
+      expect(results.map((result) => result.status === "rejected" ? String(result.reason) : result.status), `queued=${listQueuedThreadMessages(harness.db, thread.id).length}; commands=${listQueuedThreadCommands(harness, "turn.submit", thread.id).length}`).toEqual(
+        Array.from({ length: 4 }, () => "fulfilled"),
+      );
+      expect(listQueuedThreadMessages(harness.db, thread.id)).toHaveLength(3);
+    });
+  });
+});