diff --git a/codex-cli/src/cli.tsx b/codex-cli/src/cli.tsx
index 4ddd7d4914..adfc96145b 100644
--- a/codex-cli/src/cli.tsx
+++ b/codex-cli/src/cli.tsx
@@ -168,6 +168,7 @@ const cli = meow(
 
       disableResponseStorage: {
         type: "boolean",
+        default: undefined,
         description:
           "Disable server-side response storage (sends full conversation context with every request)",
       },
@@ -297,7 +298,7 @@ config = {
   disableResponseStorage:
     cli.flags.disableResponseStorage !== undefined
       ? Boolean(cli.flags.disableResponseStorage)
-      : config.disableResponseStorage,
+      : (config.disableResponseStorage ?? false),
 };
 
 // Check for updates after loading config. This is important because we write state file in
diff --git a/codex-cli/src/utils/config.ts b/codex-cli/src/utils/config.ts
index 566e084d9b..fb9e1ad770 100644
--- a/codex-cli/src/utils/config.ts
+++ b/codex-cli/src/utils/config.ts
@@ -365,7 +365,7 @@ export const loadConfig = (
     instructions: combinedInstructions,
     notify: storedConfig.notify === true,
     approvalMode: storedConfig.approvalMode,
-    disableResponseStorage: storedConfig.disableResponseStorage ?? false,
+    disableResponseStorage: storedConfig.disableResponseStorage === true,
   };
 
   // -----------------------------------------------------------------------
diff --git a/codex-cli/tests/disableResponseStorage.agentLoop.test.ts b/codex-cli/tests/disableResponseStorage.agentLoop.test.ts
new file mode 100644
index 0000000000..77dee42fff
--- /dev/null
+++ b/codex-cli/tests/disableResponseStorage.agentLoop.test.ts
@@ -0,0 +1,79 @@
+/**
+ * codex-cli/tests/disableResponseStorage.agentLoop.test.ts
+ *
+ * Verifies AgentLoop's request-building logic for both values of
+ * disableResponseStorage.
+ */
+
+import { describe, it, expect, vi } from "vitest";
+import { AgentLoop } from "../src/utils/agent/agent-loop";
+import type { AppConfig } from "../src/utils/config";
+
+/* ─────────── 1.  Spy + module mock ──────────────────────────────── */
+const createSpy = vi.fn().mockResolvedValue({
+  data: { id: "resp_123", status: "completed", output: [] },
+});
+
+vi.mock("openai", () => ({
+  default: class {
+    public responses = { create: createSpy };
+  },
+  APIConnectionTimeoutError: class extends Error {},
+}));
+
+/* ─────────── 2.  Parametrised tests ─────────────────────────────── */
+describe.each([
+  { flag: true, title: "omits previous_response_id & sets store:false" },
+  { flag: false, title: "sends previous_response_id & allows store:true" },
+])("AgentLoop with disableResponseStorage=%s", ({ flag, title }) => {
+  /* build a fresh config for each case */
+  const cfg: AppConfig = {
+    model: "o4-mini",
+    provider: "openai",
+    instructions: "",
+    disableResponseStorage: flag,
+    notify: false,
+  };
+
+  it(title, async () => {
+    /* reset spy per iteration */
+    createSpy.mockClear();
+
+    const loop = new AgentLoop({
+      model: cfg.model,
+      provider: cfg.provider,
+      config: cfg,
+      instructions: "",
+      approvalPolicy: "suggest",
+      disableResponseStorage: flag,
+      additionalWritableRoots: [],
+      onItem() {},
+      onLoading() {},
+      getCommandConfirmation: async () => ({ review: "approve" }),
+      onLastResponseId() {},
+    });
+
+    await loop.run([{ type: "text", content: "hello" }]);
+    expect(createSpy).toHaveBeenCalledTimes(1);
+
+    const payload = createSpy.mock.calls[0][0];
+
+    if (flag) {
+      /* behaviour when ZDR is *on* */
+      expect(payload).not.toHaveProperty("previous_response_id");
+      payload.input.forEach((m: any) =>
+        expect(m.store === undefined ? false : m.store).toBe(false),
+      );
+    } else {
+      /* behaviour when ZDR is *off* */
+      expect(payload).toHaveProperty("previous_response_id");
+      // first user message is usually non-stored; assistant messages will be stored
+      // so here we just assert the property is not forcibly set to false
+      payload.input.forEach((m: any) => {
+        if ("store" in m) {
+          expect(m.store).not.toBe(false);
+        }
+      });
+    }
+  });
+});
diff --git a/codex-cli/tests/disableResponseStorage.test.ts b/codex-cli/tests/disableResponseStorage.test.ts
new file mode 100644
index 0000000000..d3f632fdde
--- /dev/null
+++ b/codex-cli/tests/disableResponseStorage.test.ts
@@ -0,0 +1,42 @@
+/**
+ * codex/codex-cli/tests/disableResponseStorage.test.ts
+ */
+
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+
+import { loadConfig, saveConfig } from "../src/utils/config";
+
+const sandboxHome = mkdtempSync(join(tmpdir(), "codex-home-"));
+const codexDir = join(sandboxHome, ".codex");
+const yamlPath = join(codexDir, "config.yaml");
+
+describe("disableResponseStorage persistence", () => {
+  beforeAll(() => {
+    // mkdir -p ~/.codex inside the sandbox
+    rmSync(codexDir, { recursive: true, force: true });
+    require("fs").mkdirSync(codexDir, { recursive: true });
+
+    // seed YAML with ZDR enabled
+    writeFileSync(yamlPath, "model: o4-mini\ndisableResponseStorage: true\n");
+  });
+
+  afterAll(() => {
+    rmSync(sandboxHome, { recursive: true, force: true });
+  });
+
+  it("keeps disableResponseStorage=true across load/save cycle", async () => {
+    // 1️⃣ explicitly load the sandbox file
+    const cfg1 = loadConfig(yamlPath);
+    expect(cfg1.disableResponseStorage).toBe(true);
+
+    // 2️⃣ save right back to the same file
+    await saveConfig(cfg1, yamlPath);
+
+    // 3️⃣ reload and re-assert
+    const cfg2 = loadConfig(yamlPath);
+    expect(cfg2.disableResponseStorage).toBe(true);
+  });
+});