diff --git a/neutron/services/trunk/drivers/linuxbridge/agent/driver.py b/neutron/services/trunk/drivers/linuxbridge/agent/driver.py
index 238906f6ca2..0eb2d2044fc 100644
--- a/neutron/services/trunk/drivers/linuxbridge/agent/driver.py
+++ b/neutron/services/trunk/drivers/linuxbridge/agent/driver.py
@@ -136,7 +136,7 @@ class _TrunkAPI(object):
         except resources_rpc.ResourceNotFound:
             return None
         except oslo_messaging.RemoteError as e:
-            if 'CallbackNotFound' not in str(e):
+            if e.exc_type != 'CallbackNotFound':
                 raise
             LOG.debug("Trunk plugin disabled on server. Assuming port %s is "
                       "not a trunk.", port_id)