diff --git a/ironic/conductor/manager.py b/ironic/conductor/manager.py
index 0c14309336..65e6dc2a92 100644
--- a/ironic/conductor/manager.py
+++ b/ironic/conductor/manager.py
@@ -219,7 +219,12 @@ class ConductorManager(base_manager.BaseConductorManager):
 
         driver_factory.check_and_update_node_interfaces(node_obj)
 
+        # NOTE(dtantsur): if we're updating the driver from an invalid value,
+        # loading the old driver may be impossible. Since we only need to
+        # update the node record in the database, skip loading the driver
+        # completely.
         with task_manager.acquire(context, node_id, shared=False,
+                                  load_driver=False,
                                   purpose='node update') as task:
             # Prevent instance_uuid overwriting
             if ('instance_uuid' in delta and node_obj.instance_uuid
diff --git a/ironic/conductor/task_manager.py b/ironic/conductor/task_manager.py
index c519379a64..804d8e4a2c 100644
--- a/ironic/conductor/task_manager.py
+++ b/ironic/conductor/task_manager.py
@@ -170,7 +170,8 @@ class TaskManager(object):
     """
 
     def __init__(self, context, node_id, shared=False,
-                 purpose='unspecified action', retry=True):
+                 purpose='unspecified action', retry=True,
+                 load_driver=True):
         """Create a new TaskManager.
 
         Acquire a lock on a node. The lock can be either shared or
@@ -184,6 +185,9 @@ class TaskManager(object):
                        lock. Default: False.
         :param purpose: human-readable purpose to put to debug logs.
         :param retry: whether to retry locking if it fails. Default: True.
+        :param load_driver: whether to load the ``driver`` object. Set this to
+                            False if loading the driver is undesired or
+                            impossible.
         :raises: DriverNotFound
         :raises: InterfaceNotFoundInEntrypoint
         :raises: NodeNotFound
@@ -229,7 +233,10 @@ class TaskManager(object):
                 context, self.node.id)
             self.volume_targets = objects.VolumeTarget.list_by_node_id(
                 context, self.node.id)
-            self.driver = driver_factory.build_driver_for_task(self)
+            if load_driver:
+                self.driver = driver_factory.build_driver_for_task(self)
+            else:
+                self.driver = None
 
         except Exception:
             with excutils.save_and_reraise_exception():
diff --git a/ironic/tests/unit/conductor/test_manager.py b/ironic/tests/unit/conductor/test_manager.py
index 0cfb7de9ec..f34ee34874 100644
--- a/ironic/tests/unit/conductor/test_manager.py
+++ b/ironic/tests/unit/conductor/test_manager.py
@@ -625,6 +625,16 @@ class UpdateNodeTestCase(mgr_utils.ServiceSetUpMixin, db_base.DbTestCase):
         node.refresh()
         self.assertEqual(existing_driver, node.driver)
 
+    def test_update_node_from_invalid_driver(self):
+        existing_driver = 'fake-hardware'
+        wrong_driver = 'wrong-driver'
+        node = obj_utils.create_test_node(self.context, driver=wrong_driver)
+        node.driver = existing_driver
+        result = self.service.update_node(self.context, node)
+        self.assertEqual(existing_driver, result.driver)
+        node.refresh()
+        self.assertEqual(existing_driver, node.driver)
+
     UpdateInterfaces = namedtuple('UpdateInterfaces', ('old', 'new'))
     # NOTE(dtantsur): "old" interfaces here do not match the defaults, so that
     # we can test resetting them.
diff --git a/ironic/tests/unit/conductor/test_task_manager.py b/ironic/tests/unit/conductor/test_task_manager.py
index 7043fee5a0..1cb61441ff 100644
--- a/ironic/tests/unit/conductor/test_task_manager.py
+++ b/ironic/tests/unit/conductor/test_task_manager.py
@@ -79,6 +79,24 @@ class TaskManagerTestCase(db_base.DbTestCase):
         release_mock.assert_called_once_with(self.context, self.host,
                                              self.node.id)
 
+    def test_no_driver(self, get_voltgt_mock, get_volconn_mock,
+                       get_portgroups_mock, get_ports_mock,
+                       build_driver_mock, reserve_mock, release_mock,
+                       node_get_mock):
+        reserve_mock.return_value = self.node
+        with task_manager.TaskManager(self.context, 'fake-node-id',
+                                      load_driver=False) as task:
+            self.assertEqual(self.context, task.context)
+            self.assertEqual(self.node, task.node)
+            self.assertEqual(get_ports_mock.return_value, task.ports)
+            self.assertEqual(get_portgroups_mock.return_value, task.portgroups)
+            self.assertEqual(get_volconn_mock.return_value,
+                             task.volume_connectors)
+            self.assertEqual(get_voltgt_mock.return_value, task.volume_targets)
+            self.assertIsNone(task.driver)
+            self.assertFalse(task.shared)
+        self.assertFalse(build_driver_mock.called)
+
     def test_excl_nested_acquire(
             self, get_voltgt_mock, get_volconn_mock, get_portgroups_mock,
             get_ports_mock, build_driver_mock,
diff --git a/releasenotes/notes/broken-driver-update-fc5303340080ef04.yaml b/releasenotes/notes/broken-driver-update-fc5303340080ef04.yaml
new file mode 100644
index 0000000000..057de4dd93
--- /dev/null
+++ b/releasenotes/notes/broken-driver-update-fc5303340080ef04.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    A bug has been fixed in the node update code that could cause the nodes
+    to become not updatable if their driver is no longer available.