diff --git a/opendbc_repo/opendbc/safety/tests/test_polestar_counters.py b/opendbc_repo/opendbc/safety/tests/test_polestar_counters.py
new file mode 100644
index 0000000000..c8b9dae6d2
--- /dev/null
+++ b/opendbc_repo/opendbc/safety/tests/test_polestar_counters.py
@@ -0,0 +1,88 @@
+"""Polestar modulo-15 receiver counters retain physical-source watchdogs."""
+import unittest
+
+from opendbc.safety.tests import test_volvo_cma as cma
+
+
+class TestPolestarCounters(unittest.TestCase):
+  PARAM = 5
+  setUp = cma.TestVolvoCMASafety.setUp
+  reset = cma.TestVolvoCMASafety.reset
+  rx = cma.TestVolvoCMASafety.rx
+  tx = cma.TestVolvoCMASafety.tx
+  base_sources = cma.TestVolvoCMASafety.sources
+  feed = cma.TestVolvoCMASafety.feed
+  relay = cma.TestVolvoCMASafety.relay
+  lca_command = cma.TestVolvoCMASafety.lca_command
+
+  def sources(self, sample=0, one=None, two=None, **kwargs):
+    messages = self.base_sources(sample=sample, **kwargs)
+    result = []
+    for address, payload, bus in messages:
+      if address == 0x69:
+        data = bytearray(payload)
+        data[1] = (data[1] & 0xF0) | (sample * 2 % 15 if one is None else one)
+        data[5] = (data[5] & 0xF0) | (sample * 4 % 15 if two is None else two)
+        payload = cma.checksummed((address, data, bus))[1]
+      result.append((address, payload, bus))
+    return result
+
+  def test_nominal_and_jittered_counters_wrap_without_losing_permission(self):
+    self.feed()
+    one = two = 0
+    for sample in range(1, 46):
+      self.safety.set_timer(10000 + sample * 20000)
+      one = (one + (1, 2, 3)[sample % 3]) % 15
+      two = (two + (3, 4, 5)[sample % 3]) % 15
+      self.feed(sample=sample, one=one, two=two)
+      self.assertTrue(self.tx(self.lca_command()))
+
+  def test_each_frozen_or_jumped_clock_withdraws_permission(self):
+    for clock, delta in (('one', 0), ('one', 7), ('two', 0), ('two', 8)):
+      with self.subTest(clock=clock, delta=delta):
+        self.reset()
+        self.feed()
+        rejected = False
+        for sample in range(1, 12):
+          self.safety.set_timer(10000 + sample * 20000)
+          for message in self.sources(sample=sample, **{clock: sample * delta % 15}):
+            accepted = self.rx(message)
+            if message[0] == 0x69:
+              rejected |= not accepted
+            else:
+              self.assertTrue(accepted)
+          self.safety.safety_tick()
+        self.assertTrue(rejected)
+        self.assertFalse(self.safety.safety_config_valid())
+        self.assertFalse(self.safety.get_controls_allowed())
+        self.assertFalse(self.tx(self.lca_command()))
+
+  def test_invalid_nibbles_and_checksum_fail_closed(self):
+    for one, two, corrupt in ((15, 0, False), (0, 15, False), (0, 0, True)):
+      with self.subTest(one=one, two=two, corrupt=corrupt):
+        self.reset()
+        self.feed()
+        message = next(m for m in self.sources(one=one, two=two) if m[0] == 0x69)
+        if corrupt:
+          data = bytearray(message[1])
+          data[2] ^= 1
+          message = message[0], bytes(data), message[2]
+        self.assertFalse(self.rx(message))
+        self.safety.safety_tick()
+        self.assertFalse(self.safety.safety_config_valid())
+        self.assertFalse(self.safety.get_controls_allowed())
+        self.assertFalse(self.tx(self.lca_command()))
+
+  def test_healthy_steps_clear_secondary_counter_error_tolerance(self):
+    self.feed()
+    # A single duplicate is within the shared tolerance, then healthy frames
+    # must recover it rather than accumulate isolated errors indefinitely.
+    for sample in range(1, 30):
+      self.safety.set_timer(10000 + sample * 20000)
+      self.feed(sample=sample)
+      if sample % 3 == 0:
+        message = next(m for m in self.sources(sample=sample) if m[0] == 0x69)
+        self.assertTrue(self.rx(message))
+    self.assertTrue(self.safety.safety_config_valid())
+    self.assertTrue(self.safety.get_controls_allowed())
+    self.assertTrue(self.tx(self.lca_command()))
diff --git a/prebuilt.json b/prebuilt.json
index 5eb522bd7d..d2af4e24ba 100644
--- a/prebuilt.json
+++ b/prebuilt.json
@@ -1 +1 @@
-{"protected_inventory_sha256": "e1d8efe44f569c1ef078abb2b7c89c337e35ac26b0e330d35fa0b917826ffd40", "schema_version": 1}
+{"protected_inventory_sha256": "86d751c8e06e09bd36f30694fcca31f06823de732027e443fe92a56a699c88ed", "schema_version": 1}