diff --git a/nova/objects/instance_numa_topology.py b/nova/objects/instance_numa_topology.py
index 56a1bb1e350a..3872d6994541 100644
--- a/nova/objects/instance_numa_topology.py
+++ b/nova/objects/instance_numa_topology.py
@@ -66,9 +66,6 @@ class InstanceNUMACell(base.NovaObject,
         if 'pagesize' not in kwargs:
             self.pagesize = None
             self.obj_reset_changes(['pagesize'])
-        if 'cpu_topology' not in kwargs:
-            self.cpu_topology = None
-            self.obj_reset_changes(['cpu_topology'])
         if 'cpu_pinning' not in kwargs:
             self.cpu_pinning = None
             self.obj_reset_changes(['cpu_pinning_raw'])
@@ -110,7 +107,7 @@ class InstanceNUMACell(base.NovaObject,
         cpu_list = sorted(list(self.cpuset))
 
         threads = 0
-        if self.cpu_topology:
+        if ('cpu_topology' in self) and self.cpu_topology:
             threads = self.cpu_topology.threads
         if threads == 1:
             threads = 0
diff --git a/nova/tests/unit/virt/test_hardware.py b/nova/tests/unit/virt/test_hardware.py
index 2e4bb54d1f7c..947accbdeb08 100644
--- a/nova/tests/unit/virt/test_hardware.py
+++ b/nova/tests/unit/virt/test_hardware.py
@@ -1840,10 +1840,12 @@ class HelperMethodsTestCase(test.NoDBTestCase):
             cells=[
                 objects.InstanceNUMACell(
                     id=0, cpuset=set([0, 1]), memory=256, pagesize=2048,
-                    cpu_pinning={0: 0, 1: 1}),
+                    cpu_pinning={0: 0, 1: 1},
+                    cpu_topology=None),
                 objects.InstanceNUMACell(
                     id=1, cpuset=set([2]), memory=256, pagesize=2048,
-                    cpu_pinning={2: 3}),
+                    cpu_pinning={2: 3},
+                    cpu_topology=None),
         ])
         self.context = context.RequestContext('fake-user',
                                               'fake-project')
diff --git a/nova/virt/hardware.py b/nova/virt/hardware.py
index c8b94d42b710..4ee1df14fd5d 100644
--- a/nova/virt/hardware.py
+++ b/nova/virt/hardware.py
@@ -571,7 +571,8 @@ def _get_desirable_cpu_topologies(flavor, image_meta, allow_threads=True,
     if numa_topology:
         min_requested_threads = None
         cell_topologies = [cell.cpu_topology for cell in numa_topology.cells
-                           if cell.cpu_topology]
+                           if ('cpu_topology' in cell
+                               and cell.cpu_topology)]
         if cell_topologies:
             min_requested_threads = min(
                     topo.threads for topo in cell_topologies)
@@ -1693,6 +1694,7 @@ def instance_topology_from_instance(instance):
                     cpuset=set(cell['cpuset']),
                     memory=cell['memory'],
                     pagesize=cell.get('pagesize'),
+                    cpu_topology=cell.get('cpu_topology'),
                     cpu_pinning=cell.get('cpu_pinning_raw'),
                     cpu_policy=cell.get('cpu_policy'),
                     cpu_thread_policy=cell.get('cpu_thread_policy'),