diff --git a/tests/safety/common.py b/tests/safety/common.py
index 3b29a64..9083f08 100644
--- a/tests/safety/common.py
+++ b/tests/safety/common.py
@@ -1,6 +1,8 @@
+import os
 import abc
 import struct
 import unittest
+import importlib
 import numpy as np
 from typing import Optional, List, Dict
 from opendbc.can.packer import CANPacker  # pylint: disable=import-error
@@ -411,3 +413,28 @@ class PandaSafetyTest(PandaSafetyTestBase):
     # past threshold
     self.safety.safety_rx_hook(self._speed_msg(self.STANDSTILL_THRESHOLD + 1))
     self.assertTrue(self.safety.get_vehicle_moving())
+
+  def test_tx_hook_on_wrong_safety_mode(self):
+    files = os.listdir(os.path.dirname(os.path.realpath(__file__)))
+    test_files = [f for f in files if f.startswith("test_") and f.endswith(".py")]
+
+    current_test = self.__class__.__name__
+
+    all_tx = []
+    for tf in test_files:
+      test = importlib.import_module("panda.tests.safety."+tf[:-3])
+      for attr in dir(test):
+        if attr.startswith("Test") and attr != current_test:
+          tx = getattr(getattr(test, attr), "TX_MSGS")
+          if tx is not None:
+            all_tx.append(tx)
+
+    # make sure we got all the msgs
+    self.assertTrue(len(all_tx) >= len(test_files)-1)
+
+    for tx_msgs in all_tx:
+      for addr, bus in tx_msgs:
+        msg = make_msg(addr, bus)
+        self.safety.set_controls_allowed(1)
+        self.assertFalse(self._tx(msg))
+
diff --git a/tests/safety/test_gm.py b/tests/safety/test_gm.py
index 6b787d3..13576d8 100644
--- a/tests/safety/test_gm.py
+++ b/tests/safety/test_gm.py
@@ -24,7 +24,7 @@ class TestGmSafety(common.PandaSafetyTest):
   TX_MSGS = [[384, 0], [1033, 0], [1034, 0], [715, 0], [880, 0],  # pt bus
              [161, 1], [774, 1], [776, 1], [784, 1],  # obs bus
              [789, 2],  # ch bus
-             [0x104c006c, 3], [0x10400060]]  # gmlan
+             [0x104c006c, 3], [0x10400060, 3]]  # gmlan
   STANDSTILL_THRESHOLD = 0
   RELAY_MALFUNCTION_ADDR = 384
   RELAY_MALFUNCTION_BUS = 0