diff --git a/nova/api/openstack/compute/quota_classes.py b/nova/api/openstack/compute/quota_classes.py
index e09631b396a6..efc01dd781ac 100644
--- a/nova/api/openstack/compute/quota_classes.py
+++ b/nova/api/openstack/compute/quota_classes.py
@@ -28,7 +28,6 @@ from nova import utils
 
 
 QUOTAS = quota.QUOTAS
-ALIAS = "os-quota-class-sets"
 
 # Quotas that are only enabled by specific extensions
 EXTENDED_QUOTAS = {'server_groups': 'os-server-group-quotas',
@@ -41,10 +40,10 @@ class QuotaClassSetsController(wsgi.Controller):
 
     def __init__(self, **kwargs):
         self.supported_quotas = QUOTAS.resources
-        extension_info = kwargs.pop('extension_info').get_extensions()
+        # TODO(jichenjc): need fix v2 and v2.1 API difference here see bug
+        # 1693168 for more info
         for resource, extension in EXTENDED_QUOTAS.items():
-            if extension not in extension_info:
-                self.supported_quotas.remove(resource)
+            self.supported_quotas.remove(resource)
 
     def _format_quota_set(self, quota_class, quota_set):
         """Convert the quota object to a result dict."""
@@ -89,22 +88,3 @@ class QuotaClassSetsController(wsgi.Controller):
 
         values = QUOTAS.get_class_quotas(context, quota_class)
         return self._format_quota_set(None, values)
-
-
-class QuotaClasses(extensions.V21APIExtensionBase):
-    """Quota classes management support."""
-
-    name = "QuotaClasses"
-    alias = ALIAS
-    version = 1
-
-    def get_resources(self):
-        resources = []
-        res = extensions.ResourceExtension(
-            ALIAS,
-            QuotaClassSetsController(extension_info=self.extension_info))
-        resources.append(res)
-        return resources
-
-    def get_controller_extensions(self):
-        return []
diff --git a/nova/api/openstack/compute/routes.py b/nova/api/openstack/compute/routes.py
index c216e22203cb..0c35ecb375ea 100644
--- a/nova/api/openstack/compute/routes.py
+++ b/nova/api/openstack/compute/routes.py
@@ -61,6 +61,7 @@ from nova.api.openstack.compute import migrate_server
 from nova.api.openstack.compute import migrations
 from nova.api.openstack.compute import multinic
 from nova.api.openstack.compute import pause_server
+from nova.api.openstack.compute import quota_classes
 from nova.api.openstack.compute import quota_sets
 from nova.api.openstack.compute import remote_consoles
 from nova.api.openstack.compute import rescue
@@ -209,6 +210,10 @@ migrations_controller = functools.partial(_create_controller,
     migrations.MigrationsController, [], [])
 
 
+quota_classes_controller = functools.partial(_create_controller,
+    quota_classes.QuotaClassSetsController, [], [])
+
+
 quota_set_controller = functools.partial(_create_controller,
     quota_sets.QuotaSetsController, [], [])
 
@@ -484,6 +489,10 @@ ROUTE_LIST = (
     ('/os-migrations', {
         'GET': [migrations_controller, 'index']
     }),
+    ('/os-quota-class-sets/{id}', {
+        'GET': [quota_classes_controller, 'show'],
+        'PUT': [quota_classes_controller, 'update']
+    }),
     ('/os-quota-sets/{id}', {
         'GET': [quota_set_controller, 'show'],
         'PUT': [quota_set_controller, 'update'],
diff --git a/setup.cfg b/setup.cfg
index 53d8e9a24692..8f55a1bfe5f7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -82,7 +82,6 @@ nova.api.v21.extensions =
     multiple_create = nova.api.openstack.compute.multiple_create:MultipleCreate
     networks = nova.api.openstack.compute.networks:Networks
     networks_associate = nova.api.openstack.compute.networks_associate:NetworksAssociate
-    quota_classes = nova.api.openstack.compute.quota_classes:QuotaClasses
     remote_consoles = nova.api.openstack.compute.remote_consoles:RemoteConsoles
     security_group_default_rules = nova.api.openstack.compute.security_group_default_rules:SecurityGroupDefaultRules
     security_groups = nova.api.openstack.compute.security_groups:SecurityGroups