diff --git a/starpilot/common/starpilot_functions.py b/starpilot/common/starpilot_functions.py
index 538877dd3..e137b4ded 100644
--- a/starpilot/common/starpilot_functions.py
+++ b/starpilot/common/starpilot_functions.py
@@ -14,6 +14,7 @@ from openpilot.common.params import Params
 from openpilot.common.time_helpers import system_time_valid
 from openpilot.system.athena.registration import register
 from openpilot.system.hardware import HARDWARE
+from openpilot.system.hardware.hw import Paths
 from openpilot.system.version import get_build_metadata
 
 from openpilot.starpilot.assets.theme_manager import ThemeManager
@@ -27,6 +28,56 @@ from openpilot.starpilot.common.starpilot_variables import (
 )
 
 
+def _normalize_dongle_id(value):
+  if isinstance(value, bytes):
+    value = value.decode("utf-8", errors="ignore")
+  if value is None:
+    return None
+  value = str(value).strip()
+  return value or None
+
+
+def _read_persisted_stock_dongle_id():
+  persisted_dongle_id_path = Path(Paths.persist_root()) / "comma" / "dongle_id"
+  if not persisted_dongle_id_path.is_file():
+    return None
+  return _normalize_dongle_id(persisted_dongle_id_path.read_text())
+
+
+def _ensure_stock_dongle_id(params):
+  current_dongle_id = _normalize_dongle_id(params.get("DongleId"))
+  konik_dongle_id = _normalize_dongle_id(params.get("KonikDongleId"))
+  stock_dongle_id = _normalize_dongle_id(params.get("StockDongleId"))
+
+  if stock_dongle_id not in (None, konik_dongle_id):
+    return stock_dongle_id
+
+  candidate = _read_persisted_stock_dongle_id()
+  if candidate in (None, konik_dongle_id):
+    candidate = current_dongle_id if current_dongle_id != konik_dongle_id else None
+
+  if candidate is not None and candidate != stock_dongle_id:
+    params.put("StockDongleId", candidate)
+
+  return candidate
+
+
+def sync_konik_dongle_id(params):
+  current_dongle_id = _normalize_dongle_id(params.get("DongleId"))
+  konik_dongle_id = _normalize_dongle_id(params.get("KonikDongleId"))
+  stock_dongle_id = _ensure_stock_dongle_id(params)
+
+  if use_konik_server():
+    if konik_dongle_id is None:
+      konik_dongle_id = _normalize_dongle_id(register(show_spinner=True, register_konik=True))
+      if konik_dongle_id is not None:
+        params.put("KonikDongleId", konik_dongle_id)
+    if konik_dongle_id is not None and current_dongle_id != konik_dongle_id:
+      params.put("DongleId", konik_dongle_id)
+  elif current_dongle_id == konik_dongle_id and stock_dongle_id is not None:
+    params.put("DongleId", stock_dongle_id)
+
+
 def seed_desktop_theme_assets():
   params = Params()
   params_memory = Params(memory=True)
@@ -73,14 +124,7 @@ def starpilot_boot_functions(build_metadata, params):
   StarPilotVariables()
   ThemeManager(params, params_memory, boot_run=True).update_active_theme(time_validated=system_time_valid(), starpilot_toggles=get_starpilot_toggles(), boot_run=True)
 
-  if use_konik_server():
-    if params.get("KonikDongleId") is not None:
-      params.put("DongleId", params.get("KonikDongleId"))
-    else:
-      params.put("KonikDongleId", register(show_spinner=True, register_konik=True))
-      params.put("DongleId", params.get("KonikDongleId"))
-  elif params.get("DongleId") == params.get("KonikDongleId"):
-    params.put("DongleId", params.get("StockDongleId"))
+  sync_konik_dongle_id(params)
 
   def boot_thread():
     while not system_time_valid():
diff --git a/starpilot/common/tests/test_starpilot_functions.py b/starpilot/common/tests/test_starpilot_functions.py
new file mode 100644
index 000000000..7ff6059e2
--- /dev/null
+++ b/starpilot/common/tests/test_starpilot_functions.py
@@ -0,0 +1,61 @@
+from openpilot.starpilot.common import starpilot_functions as spf
+
+
+class FakeParams:
+  def __init__(self, values=None):
+    self.values = dict(values or {})
+
+  def get(self, key):
+    return self.values.get(key)
+
+  def put(self, key, value):
+    self.values[key] = value
+
+
+def test_sync_konik_dongle_id_preserves_stock_id_before_switching(monkeypatch, tmp_path):
+  monkeypatch.setattr(spf.Paths, "persist_root", staticmethod(lambda: str(tmp_path)))
+  monkeypatch.setattr(spf, "use_konik_server", lambda: True)
+  monkeypatch.setattr(spf, "register", lambda **kwargs: "konik-dongle")
+
+  params = FakeParams({"DongleId": "stock-dongle"})
+
+  spf.sync_konik_dongle_id(params)
+
+  assert params.get("StockDongleId") == "stock-dongle"
+  assert params.get("KonikDongleId") == "konik-dongle"
+  assert params.get("DongleId") == "konik-dongle"
+
+
+def test_sync_konik_dongle_id_restores_stock_id_from_persist(monkeypatch, tmp_path):
+  persist_root = tmp_path / "persist"
+  persisted_dongle_id_path = persist_root / "comma" / "dongle_id"
+  persisted_dongle_id_path.parent.mkdir(parents=True, exist_ok=True)
+  persisted_dongle_id_path.write_text("stock-dongle")
+
+  monkeypatch.setattr(spf.Paths, "persist_root", staticmethod(lambda: str(persist_root)))
+  monkeypatch.setattr(spf, "use_konik_server", lambda: False)
+
+  params = FakeParams({
+    "DongleId": "konik-dongle",
+    "KonikDongleId": "konik-dongle",
+  })
+
+  spf.sync_konik_dongle_id(params)
+
+  assert params.get("StockDongleId") == "stock-dongle"
+  assert params.get("DongleId") == "stock-dongle"
+
+
+def test_sync_konik_dongle_id_skips_missing_stock_backup(monkeypatch, tmp_path):
+  monkeypatch.setattr(spf.Paths, "persist_root", staticmethod(lambda: str(tmp_path)))
+  monkeypatch.setattr(spf, "use_konik_server", lambda: False)
+
+  params = FakeParams({
+    "DongleId": "konik-dongle",
+    "KonikDongleId": "konik-dongle",
+  })
+
+  spf.sync_konik_dongle_id(params)
+
+  assert params.get("DongleId") == "konik-dongle"
+  assert params.get("StockDongleId") is None