diff --git a/nova/compute/utils.py b/nova/compute/utils.py
index ace290e2ff69..272e88233c42 100644
--- a/nova/compute/utils.py
+++ b/nova/compute/utils.py
@@ -734,25 +734,6 @@ def downsize_quota_delta(context, instance):
     return resize_quota_delta(context, new_flavor, old_flavor, 1, -1)
 
 
-def reserve_quota_delta(context, deltas, instance):
-    """If there are deltas to reserve, construct a Quotas object and
-    reserve the deltas for the given project.
-
-    :param context:    The nova request context.
-    :param deltas:     A dictionary of the proposed delta changes.
-    :param instance:   The instance we're operating on, so that
-                       quotas can use the correct project_id/user_id.
-    :return: nova.objects.quotas.Quotas
-    """
-    quotas = objects.Quotas(context=context)
-    if deltas:
-        project_id, user_id = objects.quotas.ids_from_instance(context,
-                                                               instance)
-        quotas.reserve(project_id=project_id, user_id=user_id,
-                       **deltas)
-    return quotas
-
-
 def get_headroom(quotas, usages, deltas):
     headroom = {res: quotas[res] - usages[res]
                 for res in quotas.keys()}
diff --git a/nova/tests/unit/compute/test_compute_cells.py b/nova/tests/unit/compute/test_compute_cells.py
index ff82bf67fa34..29a36d22530e 100644
--- a/nova/tests/unit/compute/test_compute_cells.py
+++ b/nova/tests/unit/compute/test_compute_cells.py
@@ -650,14 +650,13 @@ class CellsConductorAPIRPCRedirect(test.NoDBTestCase):
     @mock.patch.object(objects.RequestSpec, 'get_by_instance_uuid')
     @mock.patch.object(compute_api.API, '_record_action_start')
     @mock.patch.object(compute_api.API, '_resize_cells_support')
-    @mock.patch.object(compute_utils, 'reserve_quota_delta')
     @mock.patch.object(compute_utils, 'upsize_quota_delta')
     @mock.patch.object(objects.Instance, 'save')
     @mock.patch.object(flavors, 'extract_flavor')
     @mock.patch.object(compute_api.API, '_check_auto_disk_config')
     @mock.patch.object(objects.BlockDeviceMappingList, 'get_by_instance_uuid')
     def test_resize_instance(self, _bdms, _check, _extract, _save, _upsize,
-                             _reserve, _cells, _record, _spec_get_by_uuid):
+                             _cells, _record, _spec_get_by_uuid):
         flavor = objects.Flavor(**test_flavor.fake_flavor)
         _extract.return_value = flavor
         orig_system_metadata = {}
diff --git a/nova/tests/unit/compute/test_compute_utils.py b/nova/tests/unit/compute/test_compute_utils.py
index 3f7c77390338..6d568410f63d 100644
--- a/nova/tests/unit/compute/test_compute_utils.py
+++ b/nova/tests/unit/compute/test_compute_utils.py
@@ -1097,25 +1097,6 @@ class ComputeUtilsQuotaTestCase(test.TestCase):
         deltas = compute_utils.reverse_upsize_quota_delta(self.context, inst)
         self.assertEqual(expected_deltas, deltas)
 
-    @mock.patch.object(objects.Quotas, 'reserve')
-    @mock.patch.object(objects.quotas, 'ids_from_instance')
-    def test_reserve_quota_delta(self, mock_ids_from_instance,
-                                 mock_reserve):
-        quotas = objects.Quotas(context=context)
-        inst = create_instance(self.context, params=None)
-        inst.old_flavor = flavors.get_flavor_by_name('m1.tiny')
-        inst.new_flavor = flavors.get_flavor_by_name('m1.medium')
-
-        mock_ids_from_instance.return_value = (inst.project_id, inst.user_id)
-        mock_reserve.return_value = quotas
-
-        deltas = compute_utils.upsize_quota_delta(self.context,
-                                                  inst.new_flavor,
-                                                  inst.old_flavor)
-        compute_utils.reserve_quota_delta(self.context, deltas, inst)
-        mock_reserve.assert_called_once_with(project_id=inst.project_id,
-                                             user_id=inst.user_id, **deltas)
-
     @mock.patch('nova.objects.Quotas.count_as_dict')
     def test_check_instance_quota_exceeds_with_multiple_resources(self,
                                                                   mock_count):