diff --git a/packages/cli/src/utils/clipboard.test.ts b/packages/cli/src/utils/clipboard.test.ts
new file mode 100644
index 0000000000..2cf2422269
--- /dev/null
+++ b/packages/cli/src/utils/clipboard.test.ts
@@ -0,0 +1,31 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const spawnSync = vi.hoisted(() => vi.fn());
+vi.mock("node:child_process", () => ({ spawnSync }));
+vi.mock("node:os", async (orig) => ({
+  ...(await orig<typeof import("node:os")>()),
+  platform: () => "darwin",
+}));
+
+describe("copyToClipboard", () => {
+  beforeEach(() => {
+    spawnSync.mockReset();
+    vi.resetModules();
+  });
+
+  it("does not let the tool's background owner hold our output pipes or block forever", async () => {
+    spawnSync.mockReturnValue({ status: 0 });
+    const { copyToClipboard } = await import("./clipboard.js");
+    expect(copyToClipboard("snippet")).toBe(true);
+    const opts = spawnSync.mock.calls[0]![2];
+    expect(opts.input).toBe("snippet");
+    expect(opts.stdio).toEqual(["pipe", "ignore", "ignore"]);
+    expect(opts.timeout).toBeGreaterThan(0);
+  });
+
+  it("reports not copied when the tool times out", async () => {
+    spawnSync.mockReturnValue({ status: null, error: new Error("ETIMEDOUT") });
+    const { copyToClipboard } = await import("./clipboard.js");
+    expect(copyToClipboard("snippet")).toBe(false);
+  });
+});
diff --git a/packages/cli/src/utils/clipboard.ts b/packages/cli/src/utils/clipboard.ts
index f20dad7252..51b3c52ced 100644
--- a/packages/cli/src/utils/clipboard.ts
+++ b/packages/cli/src/utils/clipboard.ts
@@ -9,6 +9,8 @@
 import { spawnSync } from "node:child_process";
 import { platform } from "node:os";
 
+const COPY_TIMEOUT_MS = 5000;
+
 interface ClipboardProvider {
   cmd: string;
   args: string[];
@@ -49,6 +51,8 @@ export function copyToClipboard(text: string): boolean {
     const res = spawnSync(provider.cmd, provider.args, {
       input: text,
       encoding: "utf-8",
+      stdio: ["pipe", "ignore", "ignore"],
+      timeout: COPY_TIMEOUT_MS,
     });
     return res.status === 0;
   } catch {