diff --git a/neutron/notifiers/nova.py b/neutron/notifiers/nova.py
index 57f636e0c06..492080d4509 100644
--- a/neutron/notifiers/nova.py
+++ b/neutron/notifiers/nova.py
@@ -57,7 +57,8 @@ class Notifier(object):
             auth=auth)
 
         extensions = [
-            ext for ext in nova_client.discover_extensions(NOVA_API_VERSION)
+            ext for ext in nova_client.discover_extensions(NOVA_API_VERSION,
+                                                           only_contrib=True)
             if ext.name == "server_external_events"]
         self.nclient = nova_client.Client(
             NOVA_API_VERSION,