diff --git a/ironic/db/sqlalchemy/api.py b/ironic/db/sqlalchemy/api.py
index f072856bbc..95baf75fde 100644
--- a/ironic/db/sqlalchemy/api.py
+++ b/ironic/db/sqlalchemy/api.py
@@ -999,9 +999,9 @@ class Connection(api.Connection):
         nodes = []
         with _session_for_write():
             query = (model_query(models.Node)
-                     .filter_by(reservation=hostname))
+                     .filter(models.Node.reservation.ilike(hostname)))
             nodes = [node['uuid'] for node in query]
-            query.update({'reservation': None})
+            query.update({'reservation': None}, synchronize_session=False)
 
         if nodes:
             nodes = ', '.join(nodes)
@@ -1014,13 +1014,14 @@ class Connection(api.Connection):
         nodes = []
         with _session_for_write():
             query = (model_query(models.Node)
-                     .filter_by(reservation=hostname))
+                     .filter(models.Node.reservation.ilike(hostname)))
             query = query.filter(models.Node.target_power_state != sql.null())
             nodes = [node['uuid'] for node in query]
             query.update({'target_power_state': None,
                           'last_error': _("Pending power operation was "
                                           "aborted due to conductor "
-                                          "restart")})
+                                          "restart")},
+                         synchronize_session=False)
 
         if nodes:
             nodes = ', '.join(nodes)
diff --git a/ironic/tests/unit/db/test_conductor.py b/ironic/tests/unit/db/test_conductor.py
index ebde348172..1ae38de88b 100644
--- a/ironic/tests/unit/db/test_conductor.py
+++ b/ironic/tests/unit/db/test_conductor.py
@@ -179,13 +179,16 @@ class DbConductorTestCase(base.DbTestCase):
         node1 = self.dbapi.create_node({'reservation': 'hostname1'})
         node2 = self.dbapi.create_node({'reservation': 'hostname2'})
         node3 = self.dbapi.create_node({'reservation': None})
+        node4 = self.dbapi.create_node({'reservation': 'hostName1'})
         self.dbapi.clear_node_reservations_for_conductor('hostname1')
         node1 = self.dbapi.get_node_by_id(node1.id)
         node2 = self.dbapi.get_node_by_id(node2.id)
         node3 = self.dbapi.get_node_by_id(node3.id)
+        node4 = self.dbapi.get_node_by_id(node4.id)
         self.assertIsNone(node1.reservation)
         self.assertEqual('hostname2', node2.reservation)
         self.assertIsNone(node3.reservation)
+        self.assertIsNone(node4.reservation)
 
     def test_clear_node_target_power_state(self):
         node1 = self.dbapi.create_node({'reservation': 'hostname1',
@@ -194,16 +197,21 @@ class DbConductorTestCase(base.DbTestCase):
                                         'target_power_state': 'power on'})
         node3 = self.dbapi.create_node({'reservation': None,
                                         'target_power_state': 'power on'})
+        node4 = self.dbapi.create_node({'reservation': 'hostName1',
+                                        'target_power_state': 'power on'})
         self.dbapi.clear_node_target_power_state('hostname1')
         node1 = self.dbapi.get_node_by_id(node1.id)
         node2 = self.dbapi.get_node_by_id(node2.id)
         node3 = self.dbapi.get_node_by_id(node3.id)
+        node4 = self.dbapi.get_node_by_id(node4.id)
         self.assertIsNone(node1.target_power_state)
         self.assertIn('power operation was aborted', node1.last_error)
         self.assertEqual('power on', node2.target_power_state)
         self.assertIsNone(node2.last_error)
         self.assertEqual('power on', node3.target_power_state)
         self.assertIsNone(node3.last_error)
+        self.assertIsNone(node4.target_power_state)
+        self.assertIn('power operation was aborted', node4.last_error)
 
     @mock.patch.object(timeutils, 'utcnow', autospec=True)
     def test_get_active_hardware_type_dict_one_host_no_ht(self, mock_utcnow):
diff --git a/releasenotes/notes/caseless-conductor-restart-check-f70005fbf65f6bb6.yaml b/releasenotes/notes/caseless-conductor-restart-check-f70005fbf65f6bb6.yaml
new file mode 100644
index 0000000000..a085a04c32
--- /dev/null
+++ b/releasenotes/notes/caseless-conductor-restart-check-f70005fbf65f6bb6.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixes an issue where a node may be locked from changes if a conductor's
+    hostname case is changed before restarting the conductor service.