diff --git a/ironic/conductor/manager.py b/ironic/conductor/manager.py
index f8d5a101d2..ee0fba43be 100644
--- a/ironic/conductor/manager.py
+++ b/ironic/conductor/manager.py
@@ -468,25 +468,6 @@ class ConductorManager(periodic_task.PeriodicTasks):
 
             vendor_iface = task.driver.vendor
 
-            # NOTE(lucasagomes): Before the vendor_passthru() method was
-            # a self-contained method and each driver implemented their own
-            # version of it, now we have a common mechanism that drivers
-            # should use to expose their vendor methods. If a driver still
-            # have their own vendor_passthru() method we call it to be
-            # backward compat. This code should be removed once L opens.
-            if hasattr(vendor_iface, 'vendor_passthru'):
-                LOG.warning(_LW("Drivers implementing their own version "
-                                "of vendor_passthru() has been deprecated. "
-                                "Please update the code to use the "
-                                "@passthru decorator."))
-                vendor_iface.validate(task, method=driver_method,
-                                      **info)
-                task.spawn_after(self._spawn_worker,
-                                 vendor_iface.vendor_passthru, task,
-                                 method=driver_method, **info)
-                # NodeVendorPassthru was always async
-                return (None, True)
-
             try:
                 vendor_opts = vendor_iface.vendor_routes[driver_method]
                 vendor_func = vendor_opts['func']
diff --git a/ironic/tests/conductor/test_manager.py b/ironic/tests/conductor/test_manager.py
index 34e5a1d5f5..21041439f2 100644
--- a/ironic/tests/conductor/test_manager.py
+++ b/ironic/tests/conductor/test_manager.py
@@ -715,30 +715,6 @@ class VendorPassthruTestCase(_ServiceSetUpMixin, tests_db_base.DbTestCase):
             # Verify reservation has been cleared.
             self.assertIsNone(node.reservation)
 
-    @mock.patch.object(task_manager, 'acquire')
-    def test_vendor_passthru_backwards_compat(self, acquire_mock):
-        node = obj_utils.create_test_node(self.context, driver='fake')
-        vendor_passthru_ref = mock.Mock()
-        self._start_service()
-
-        driver = mock.Mock()
-        driver.vendor.vendor_routes = {}
-        driver.vendor.vendor_passthru = vendor_passthru_ref
-
-        task = mock.Mock()
-        task.node = node
-        task.driver = driver
-
-        acquire_mock.return_value.__enter__.return_value = task
-
-        response = self.service.vendor_passthru(
-            self.context, node.uuid, 'test_method', 'POST', {'bar': 'baz'})
-
-        self.assertEqual((None, True), response)
-        task.spawn_after.assert_called_once_with(
-            mock.ANY, vendor_passthru_ref, task, bar='baz',
-            method='test_method')
-
     def test_get_node_vendor_passthru_methods(self):
         node = obj_utils.create_test_node(self.context, driver='fake')
         fake_routes = {'test_method': {'async': True,