diff --git a/nova/api/openstack/compute/shelve.py b/nova/api/openstack/compute/shelve.py
index a606cdda9d04..10fc66fc4b3f 100644
--- a/nova/api/openstack/compute/shelve.py
+++ b/nova/api/openstack/compute/shelve.py
@@ -47,7 +47,8 @@ class ShelveController(wsgi.Controller):
             self.compute_api.shelve(context, instance)
         except exception.InstanceUnknownCell as e:
             raise exc.HTTPNotFound(explanation=e.format_message())
-        except exception.InstanceIsLocked as e:
+        except (exception.InstanceIsLocked,
+                exception.UnexpectedTaskStateError) as e:
             raise exc.HTTPConflict(explanation=e.format_message())
         except exception.InstanceInvalidState as state_error:
             common.raise_http_conflict_for_instance_invalid_state(state_error,
diff --git a/nova/tests/unit/api/openstack/compute/test_shelve.py b/nova/tests/unit/api/openstack/compute/test_shelve.py
index 257bc5366daa..d771a213abd6 100644
--- a/nova/tests/unit/api/openstack/compute/test_shelve.py
+++ b/nova/tests/unit/api/openstack/compute/test_shelve.py
@@ -15,9 +15,12 @@
 import mock
 from oslo_policy import policy as oslo_policy
 from oslo_utils.fixture import uuidsentinel
+import six
 import webob
 
 from nova.api.openstack.compute import shelve as shelve_v21
+from nova.compute import task_states
+from nova.compute import vm_states
 from nova import exception
 from nova import policy
 from nova import test
@@ -42,6 +45,22 @@ class ShelvePolicyTestV21(test.NoDBTestCase):
         self.assertRaises(webob.exc.HTTPConflict, self.controller._shelve,
                           self.req, uuidsentinel.fake, {})
 
+    @mock.patch('nova.api.openstack.common.get_instance')
+    @mock.patch('nova.objects.instance.Instance.save')
+    def test_shelve_task_state_race(self, mock_save, get_instance_mock):
+        instance = fake_instance.fake_instance_obj(
+            self.req.environ['nova.context'],
+            vm_state=vm_states.ACTIVE, task_state=None)
+        instance.launched_at = instance.created_at
+        get_instance_mock.return_value = instance
+        mock_save.side_effect = exception.UnexpectedTaskStateError(
+            instance_uuid=instance.uuid, expected=None,
+            actual=task_states.SHELVING)
+        ex = self.assertRaises(webob.exc.HTTPConflict, self.controller._shelve,
+                          self.req, uuidsentinel.fake, body={'shelve': {}})
+        self.assertIn('Conflict updating instance', six.text_type(ex))
+        mock_save.assert_called_once_with(expected_task_state=[None])
+
     @mock.patch('nova.api.openstack.common.get_instance')
     def test_unshelve_locked_server(self, get_instance_mock):
         get_instance_mock.return_value = (