diff --git a/nova/objects/numa.py b/nova/objects/numa.py
index ad9d46422180..cbfa8a242738 100644
--- a/nova/objects/numa.py
+++ b/nova/objects/numa.py
@@ -226,8 +226,12 @@ class NUMATopology(base.NovaObject):
 
     @classmethod
     def obj_from_db_obj(cls, db_obj):
-        return cls.obj_from_primitive(
-            jsonutils.loads(db_obj))
+        """Convert serialized representation to object.
+
+        Deserialize instances of this object that have been stored as JSON
+        blobs in the database.
+        """
+        return cls.obj_from_primitive(jsonutils.loads(db_obj))
 
     def __len__(self):
         """Defined so that boolean testing works the same as for lists."""
@@ -265,19 +269,3 @@ class NUMATopologyLimits(base.NovaObject):
                  'cpu_limit': len(cell.cpuset) * self.cpu_allocation_ratio,
                  'id': cell.id})
         return {'cells': cells}
-
-    @classmethod
-    def obj_from_db_obj(cls, db_obj):
-        if 'nova_object.name' in db_obj:
-            obj_topology = cls.obj_from_primitive(db_obj)
-        else:
-            # NOTE(sahid): This compatibility code needs to stay until we can
-            # guarantee that all compute nodes are using RPC API => 3.40.
-            cell = db_obj['cells'][0]
-            ram_ratio = cell['mem']['limit'] / float(cell['mem']['total'])
-            cpu_ratio = cell['cpu_limit'] / float(len(hardware.parse_cpu_spec(
-                cell['cpus'])))
-            obj_topology = NUMATopologyLimits(
-                cpu_allocation_ratio=cpu_ratio,
-                ram_allocation_ratio=ram_ratio)
-        return obj_topology
diff --git a/nova/tests/unit/objects/test_numa.py b/nova/tests/unit/objects/test_numa.py
index f6a89a5fa17c..89e84a775528 100644
--- a/nova/tests/unit/objects/test_numa.py
+++ b/nova/tests/unit/objects/test_numa.py
@@ -38,19 +38,6 @@ class _TestNUMA(object):
 
         self.assertEqual(d1, d2)
 
-    def test_from_legacy_limits(self):
-        old_style = {"cells": [
-                        {"mem": {
-                            "total": 1024,
-                            "limit": 2048},
-                         "cpu_limit": 96.0,
-                         "cpus": "0,1,2,3,4,5",
-                         "id": 0}]}
-
-        limits = objects.NUMATopologyLimits.obj_from_db_obj(old_style)
-        self.assertEqual(16.0, limits.cpu_allocation_ratio)
-        self.assertEqual(2.0, limits.ram_allocation_ratio)
-
     def test_to_legacy_limits(self):
         limits = objects.NUMATopologyLimits(
             cpu_allocation_ratio=16,