diff --git a/system/athena/registration.py b/system/athena/registration.py
index 717050fd8a..435fe8086a 100755
--- a/system/athena/registration.py
+++ b/system/athena/registration.py
@@ -2,9 +2,9 @@
 import time
 import json
 import jwt
-import pyray as rl
 from pathlib import Path
-from concurrent.futures import ThreadPoolExecutor
+import threading
+import pyray as rl
 
 from datetime import datetime, timedelta, UTC
 from openpilot.common.api import api_get
@@ -12,19 +12,42 @@ from openpilot.common.params import Params
 from openpilot.selfdrive.selfdrived.alertmanager import set_offroad_alert
 from openpilot.system.hardware import HARDWARE, PC
 from openpilot.system.hardware.hw import Paths
-from openpilot.system.ui.lib.application import gui_app
-from openpilot.system.ui.spinner import Spinner
 from openpilot.common.swaglog import cloudlog
-
+from openpilot.system.ui.spinner import Spinner
+from openpilot.system.ui.lib.application import gui_app
 
 UNREGISTERED_DONGLE_ID = "UnregisteredDevice"
 
+spinner: Spinner | None = None
+
 def is_registered_device() -> bool:
   dongle = Params().get("DongleId", encoding='utf-8')
   return dongle not in (None, UNREGISTERED_DONGLE_ID)
 
-def _get_dongle_id() -> str | None:
-  dongle_id: str | None = Params().get("DongleId", encoding='utf8')
+def _show_spinner_window(end_evt: threading.Event):
+  global spinner
+  gui_app.init_window("registering device")
+  spinner = Spinner()
+  while not end_evt.is_set():
+    rl.begin_drawing()
+    rl.clear_background(rl.BLACK)
+    spinner.render()
+    rl.end_drawing()
+  gui_app.close()
+
+def register(show_spinner=False) -> str | None:
+  """
+  All devices built since March 2024 come with all
+  info stored in /persist/. This is kept around
+  only for devices built before then.
+
+  With a backend update to take serial number instead
+  of dongle ID to some endpoints, this can be removed
+  entirely.
+  """
+  params = Params()
+
+  dongle_id: str | None = params.get("DongleId", encoding='utf8')
   if dongle_id is None and Path(Paths.persist_root()+"/comma/dongle_id").is_file():
     # not all devices will have this; added early in comma 3X production (2/28/24)
     with open(Paths.persist_root()+"/comma/dongle_id") as f:
@@ -34,19 +57,14 @@ def _get_dongle_id() -> str | None:
   if not pubkey.is_file():
     dongle_id = UNREGISTERED_DONGLE_ID
     cloudlog.warning(f"missing public key: {pubkey}")
+  elif dongle_id is None:
+    global spinner
+    spinner_thread = None
+    if show_spinner:
+      end_evt = threading.Event()
+      spinner_thread = threading.Thread(target=_show_spinner_window, args=(end_evt,))
+      spinner_thread.start()
 
-  return dongle_id
-
-def do_register(spinner = None, done_event=None) -> str | None:
-    """
-    All devices built since March 2024 come with all
-    info stored in /persist/. This is kept around
-    only for devices built before then.
-
-    With a backend update to take serial number instead
-    of dongle ID to some endpoints, this can be removed
-    entirely.
-    """
     # Create registration token, in the future, this key will make JWTs directly
     with open(Paths.persist_root()+"/comma/id_rsa.pub") as f1, open(Paths.persist_root()+"/comma/id_rsa") as f2:
       public_key = f1.read()
@@ -67,7 +85,6 @@ def do_register(spinner = None, done_event=None) -> str | None:
       if time.monotonic() - start_time > 60 and spinner:
         spinner.set_text(f"registering device - serial: {serial}, IMEI: ({imei1}, {imei2})")
 
-    dongle_id = None
     backoff = 0
     start_time = time.monotonic()
     while True:
@@ -92,29 +109,12 @@ def do_register(spinner = None, done_event=None) -> str | None:
       if time.monotonic() - start_time > 60 and spinner:
         spinner.set_text(f"registering device - serial: {serial}, IMEI: ({imei1}, {imei2})")
 
-    return dongle_id
-
-def register(show_spinner=False) -> str | None:
-  dongle_id = _get_dongle_id()
-  if not dongle_id:
-    if show_spinner:
-      with ThreadPoolExecutor(max_workers=1) as executor:
-        gui_app.init_window("Register")
-        spinner = Spinner()
-        spinner.set_text("registering device")
-        future = executor.submit(do_register, spinner)
-        while not future.done():
-          rl.begin_drawing()
-          rl.clear_background(rl.BLACK)
-          spinner.render()
-          rl.end_drawing()
-        gui_app.close()
-        dongle_id = future.result()
-    else:
-      dongle_id = do_register()
+    if spinner_thread:
+      end_evt.set()
+      spinner_thread.join()
 
   if dongle_id:
-    Params().put("DongleId", dongle_id)
+    params.put("DongleId", dongle_id)
     set_offroad_alert("Offroad_UnofficialHardware", (dongle_id == UNREGISTERED_DONGLE_ID) and not PC)
   return dongle_id