diff --git a/neutron_lib/fixture.py b/neutron_lib/fixture.py
index 03a22c392..94735fe08 100644
--- a/neutron_lib/fixture.py
+++ b/neutron_lib/fixture.py
@@ -132,20 +132,22 @@ class APIDefinitionFixture(fixtures.Fixture):
     def _setUp(self):
         for api_def in self.definitions:
             self._orig_attr_maps[api_def.ALIAS] = (
-                api_def, api_def.RESOURCE_ATTRIBUTE_MAP)
-            api_def.RESOURCE_ATTRIBUTE_MAP = copy.deepcopy(
-                api_def.RESOURCE_ATTRIBUTE_MAP)
+                api_def, {k: copy.deepcopy(v)
+                          for k, v in api_def.RESOURCE_ATTRIBUTE_MAP.items()})
         if self.backup_global_resources:
             for resource, attrs in attributes.RESOURCES.items():
                 self._orig_resources[resource] = copy.deepcopy(attrs)
         self.addCleanup(self._restore)
 
     def _restore(self):
+        # clear + repopulate so consumer refs don't change
         for alias, def_and_map in self._orig_attr_maps.items():
             api_def, attr_map = def_and_map[0], def_and_map[1]
-            api_def.RESOURCE_ATTRIBUTE_MAP = attr_map
+            api_def.RESOURCE_ATTRIBUTE_MAP.clear()
+            api_def.RESOURCE_ATTRIBUTE_MAP.update(attr_map)
         if self.backup_global_resources:
-            attributes.RESOURCES = self._orig_resources
+            attributes.RESOURCES.clear()
+            attributes.RESOURCES.update(self._orig_resources)
 
     @classmethod
     def all_api_definitions_fixture(cls):
diff --git a/neutron_lib/tests/unit/test_fixture.py b/neutron_lib/tests/unit/test_fixture.py
index b959b985d..ab0e35bfa 100644
--- a/neutron_lib/tests/unit/test_fixture.py
+++ b/neutron_lib/tests/unit/test_fixture.py
@@ -17,6 +17,7 @@ from oslo_db import options
 from oslotest import base
 
 from neutron_lib.api import attributes
+from neutron_lib.api.definitions import port
 from neutron_lib.callbacks import registry
 from neutron_lib.db import model_base
 from neutron_lib import fixture
@@ -92,3 +93,32 @@ class APIDefinitionFixtureTestCase(base.BaseTestCase):
 
     def test_all_api_definitions_fixture_with_global_backup(self):
         self._test_all_api_definitions_fixture(global_cleanup=True)
+
+    def test_global_resources_reference_updated(self):
+        resources_ref = attributes.RESOURCES
+        apis = fixture.APIDefinitionFixture()
+
+        apis.setUp()
+        attributes.RESOURCES['test_resource'] = {}
+        self.assertIn('test_resource', resources_ref)
+        attributes.RESOURCES[port.COLLECTION_NAME]['test_port_attr'] = {}
+        self.assertIn('test_port_attr',
+                      attributes.RESOURCES[port.COLLECTION_NAME])
+        apis.cleanUp()
+
+        self.assertNotIn('test_port_attr',
+                         attributes.RESOURCES[port.COLLECTION_NAME])
+        self.assertNotIn('test_resource', resources_ref)
+
+    def test_api_def_reference_updated(self):
+        api_def_ref = port.RESOURCE_ATTRIBUTE_MAP
+        apis = fixture.APIDefinitionFixture()
+
+        apis.setUp()
+        port.RESOURCE_ATTRIBUTE_MAP[port.COLLECTION_NAME]['test_attr'] = {}
+        self.assertIn('test_attr', api_def_ref[port.COLLECTION_NAME])
+        apis.cleanUp()
+
+        self.assertNotIn('test_attr',
+                         port.RESOURCE_ATTRIBUTE_MAP[port.COLLECTION_NAME])
+        self.assertNotIn('test_attr', api_def_ref[port.COLLECTION_NAME])