diff --git a/src/telegram_codex_bot/bot.py b/src/telegram_codex_bot/bot.py
index 3683a58..6a29872 100644
--- a/src/telegram_codex_bot/bot.py
+++ b/src/telegram_codex_bot/bot.py
@@ -228,6 +228,7 @@
 _runtime_stopped = False
 _codex_update_prompted_versions: set[str] = set()
 _codex_update_apply_lock: asyncio.Lock | None = None
+_CODEX_UPDATE_PROMPT_STATE_FILENAME = "codex_update_prompt_state.json"
 
 
 @dataclass
@@ -3788,15 +3789,67 @@ def _codex_update_prompt_key(result: CodexUpdateResult) -> str:
     return result.latest_version or result.message or "unknown"
 
 
+def _codex_update_prompt_state_file() -> Path:
+    """Return the state file tracking already prompted Codex CLI versions."""
+    return app_dir() / _CODEX_UPDATE_PROMPT_STATE_FILENAME
+
+
+def _load_codex_update_prompted_versions() -> set[str]:
+    """Load Codex CLI versions that have already shown an update prompt."""
+    path = _codex_update_prompt_state_file()
+    try:
+        payload = json.loads(path.read_text(encoding="utf-8"))
+    except FileNotFoundError:
+        return set()
+    except (OSError, json.JSONDecodeError) as exc:
+        logger.warning("Failed to read Codex update prompt state %s: %s", path, exc)
+        return set()
+
+    if not isinstance(payload, dict):
+        return set()
+
+    prompted_versions = payload.get("prompted_versions")
+    if not isinstance(prompted_versions, list):
+        return set()
+    return {
+        version for version in prompted_versions if isinstance(version, str) and version
+    }
+
+
+def _save_codex_update_prompted_versions(prompted_versions: set[str]) -> None:
+    """Persist Codex CLI versions that have already shown an update prompt."""
+    path = _codex_update_prompt_state_file()
+    try:
+        atomic_write_json(
+            path,
+            {"prompted_versions": sorted(prompted_versions)},
+        )
+    except OSError as exc:
+        logger.warning("Failed to write Codex update prompt state %s: %s", path, exc)
+
+
+def _mark_codex_update_prompted(key: str) -> bool:
+    """Return True when a Codex update prompt key is newly marked."""
+    persisted_versions = _load_codex_update_prompted_versions()
+    prompted_versions = persisted_versions | _codex_update_prompted_versions
+    if key in prompted_versions:
+        _codex_update_prompted_versions.update(prompted_versions)
+        return False
+
+    prompted_versions.add(key)
+    _codex_update_prompted_versions.update(prompted_versions)
+    _save_codex_update_prompted_versions(prompted_versions)
+    return True
+
+
 async def notify_codex_update_available(
     bot: Bot,
     result: CodexUpdateResult,
 ) -> None:
     """Notify allowed Telegram users that a Codex CLI update needs approval."""
     key = _codex_update_prompt_key(result)
-    if key in _codex_update_prompted_versions:
+    if not _mark_codex_update_prompted(key):
         return
-    _codex_update_prompted_versions.add(key)
 
     current = result.current_version or "unknown"
     latest = result.latest_version or "unknown"
diff --git a/tests/telegram_codex_bot/test_codex_update_prompt.py b/tests/telegram_codex_bot/test_codex_update_prompt.py
index 5a003a9..1e30a23 100644
--- a/tests/telegram_codex_bot/test_codex_update_prompt.py
+++ b/tests/telegram_codex_bot/test_codex_update_prompt.py
@@ -1,3 +1,4 @@
+import json
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
@@ -23,7 +24,11 @@ def _make_callback_update(data: str) -> MagicMock:
 
 
 @pytest.mark.asyncio
-async def test_notify_codex_update_available_sends_private_prompts(monkeypatch):
+async def test_notify_codex_update_available_sends_private_prompts(
+    monkeypatch,
+    tmp_path,
+):
+    monkeypatch.setenv("TELEGRAM_CODEX_BOT_DIR", str(tmp_path))
     monkeypatch.setattr(bot_module.config, "allowed_users", {222, 111})
     monkeypatch.setattr(bot_module, "_codex_update_prompted_versions", set())
     safe_send = AsyncMock()
@@ -48,6 +53,36 @@ async def test_notify_codex_update_available_sends_private_prompts(monkeypatch):
     keyboard = safe_send.await_args_list[0].kwargs["reply_markup"]
     assert keyboard.inline_keyboard[0][0].callback_data == CB_CODEX_UPDATE_APPLY
     assert keyboard.inline_keyboard[0][1].callback_data == CB_CODEX_UPDATE_DISMISS
+    state = json.loads((tmp_path / "codex_update_prompt_state.json").read_text())
+    assert state == {"prompted_versions": ["0.126.0"]}
+
+
+@pytest.mark.asyncio
+async def test_notify_codex_update_available_skips_persisted_prompted_version(
+    monkeypatch,
+    tmp_path,
+):
+    monkeypatch.setenv("TELEGRAM_CODEX_BOT_DIR", str(tmp_path))
+    monkeypatch.setattr(bot_module.config, "allowed_users", {222, 111})
+    (tmp_path / "codex_update_prompt_state.json").write_text(
+        json.dumps({"prompted_versions": ["0.126.0"]}),
+        encoding="utf-8",
+    )
+    monkeypatch.setattr(bot_module, "_codex_update_prompted_versions", set())
+    safe_send = AsyncMock()
+    monkeypatch.setattr(bot_module, "safe_send", safe_send)
+
+    result = CodexUpdateResult(
+        checked=True,
+        supported=True,
+        update_available=True,
+        current_version="0.125.0",
+        latest_version="0.126.0",
+    )
+
+    await bot_module.notify_codex_update_available(MagicMock(), result)
+
+    safe_send.assert_not_awaited()
 
 
 @pytest.mark.asyncio