diff --git a/neutron/extensions/l2_adjacency.py b/neutron/extensions/l2_adjacency.py
index 795a3d94272..4224e190d5a 100644
--- a/neutron/extensions/l2_adjacency.py
+++ b/neutron/extensions/l2_adjacency.py
@@ -13,20 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib.api.definitions import l2_adjacency as apidef
 from neutron_lib.api import extensions
 
 
-L2_ADJACENCY = 'l2_adjacency'
-EXTENDED_ATTRIBUTES_2_0 = {
-    'networks': {
-        L2_ADJACENCY: {'allow_post': False,
-                       'allow_put': False,
-                       'is_visible': True}
-    }
-}
-
-
-class L2_adjacency(extensions.ExtensionDescriptor):
+class L2_adjacency(extensions.APIExtensionDescriptor):
     """Extension class supporting L2 Adjacency for Routed Networks
 
     The following class is used by neutron's extension framework
@@ -34,25 +25,4 @@ class L2_adjacency(extensions.ExtensionDescriptor):
     Routed Network, exposing the same to clients.
     No new resources have been defined by this extension.
     """
-
-    @classmethod
-    def get_name(cls):
-        return "L2 Adjacency"
-
-    @classmethod
-    def get_alias(cls):
-        return "l2_adjacency"
-
-    @classmethod
-    def get_description(cls):
-        return "Display L2 Adjacency for Neutron Networks."
-
-    @classmethod
-    def get_updated(cls):
-        return "2016-04-12T16:00:00-00:00"
-
-    def get_extended_resources(self, version):
-        if version == "2.0":
-            return EXTENDED_ATTRIBUTES_2_0
-        else:
-            return {}
+    api_definition = apidef
diff --git a/neutron/services/segments/plugin.py b/neutron/services/segments/plugin.py
index 99871f93743..c14af4f1342 100644
--- a/neutron/services/segments/plugin.py
+++ b/neutron/services/segments/plugin.py
@@ -16,6 +16,7 @@
 
 from keystoneauth1 import loading as ks_loading
 import netaddr
+from neutron_lib.api.definitions import l2_adjacency as l2adj_apidef
 from neutron_lib.api.definitions import network as net_def
 from neutron_lib.api.definitions import port as port_def
 from neutron_lib.api.definitions import subnet as subnet_def
@@ -36,7 +37,6 @@ from neutron.db import api as db_api
 from neutron.db.models import segment as segment_model
 from neutron.db import models_v2
 from neutron.extensions import ip_allocation
-from neutron.extensions import l2_adjacency
 from neutron.extensions import segment
 from neutron.notifiers import batch_notifier
 from neutron.services.segments import db
@@ -57,7 +57,8 @@ class Plugin(db.SegmentDbMixin, segment.SegmentPluginBase):
 
     _instance = None
 
-    supported_extension_aliases = ["segment", "ip_allocation", "l2_adjacency"]
+    supported_extension_aliases = ["segment", "ip_allocation",
+                                   l2adj_apidef.ALIAS]
 
     def __init__(self):
         self.nova_updater = NovaSegmentNotifier()
@@ -72,7 +73,7 @@ class Plugin(db.SegmentDbMixin, segment.SegmentPluginBase):
         #                    it's a thing.
         is_adjacent = (not network_db.subnets
                        or not network_db.subnets[0].segment_id)
-        network_res[l2_adjacency.L2_ADJACENCY] = is_adjacent
+        network_res[l2adj_apidef.L2_ADJACENCY] = is_adjacent
 
     @staticmethod
     @resource_extend.extends([subnet_def.COLLECTION_NAME])
diff --git a/neutron/tests/unit/extensions/test_segment.py b/neutron/tests/unit/extensions/test_segment.py
index bcb307f81cf..970496a893c 100644
--- a/neutron/tests/unit/extensions/test_segment.py
+++ b/neutron/tests/unit/extensions/test_segment.py
@@ -17,6 +17,7 @@ import copy
 from keystoneauth1 import exceptions as ks_exc
 import mock
 import netaddr
+from neutron_lib.api.definitions import l2_adjacency as l2adj_apidef
 from neutron_lib.api.definitions import portbindings
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import exceptions
@@ -39,7 +40,6 @@ from neutron.db import db_base_plugin_v2
 from neutron.db import portbindings_db
 from neutron.db import segments_db
 from neutron.extensions import ip_allocation
-from neutron.extensions import l2_adjacency
 from neutron.extensions import segment as ext_segment
 from neutron.objects import network
 from neutron.services.segments import db
@@ -843,7 +843,7 @@ class SegmentAwareIpamTestCase(SegmentTestCase):
         request = self.new_show_request('networks', network_id)
         response = self.deserialize(self.fmt, request.get_response(self.api))
         self.assertEqual(is_adjacent,
-                         response['network'][l2_adjacency.L2_ADJACENCY])
+                         response['network'][l2adj_apidef.L2_ADJACENCY])
 
 
 class TestSegmentAwareIpam(SegmentAwareIpamTestCase):