diff --git a/neutron/plugins/ml2/plugin.py b/neutron/plugins/ml2/plugin.py
index 294deb668a..34e5add14c 100644
--- a/neutron/plugins/ml2/plugin.py
+++ b/neutron/plugins/ml2/plugin.py
@@ -939,6 +939,10 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         return self._bind_port_if_needed(port_context)
 
     def update_port_status(self, context, port_id, status, host=None):
+        """
+        Returns port_id (non-truncated uuid) if the port exists.
+        Otherwise returns None.
+        """
         updated = False
         session = context.session
         # REVISIT: Serialize this operation with a semaphore to
@@ -951,7 +955,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
             if not port:
                 LOG.warning(_("Port %(port)s updated up by agent not found"),
                             {'port': port_id})
-                return False
+                return None
             if port.status != status:
                 original_port = self._make_port_dict(port)
                 port.status = status
@@ -967,7 +971,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         if updated:
             self.mechanism_manager.update_port_postcommit(mech_context)
 
-        return True
+        return port['id']
 
     def port_bound_to_host(self, context, port_id, host):
         port_host = db.get_port_binding_host(port_id)
diff --git a/neutron/plugins/ml2/rpc.py b/neutron/plugins/ml2/rpc.py
index 553ba1f1f2..0ee8c00999 100644
--- a/neutron/plugins/ml2/rpc.py
+++ b/neutron/plugins/ml2/rpc.py
@@ -159,9 +159,9 @@ class RpcCallbacks(n_rpc.RpcCallback,
             return {'device': device,
                     'exists': port_exists}
 
-        port_exists = plugin.update_port_status(rpc_context, port_id,
-                                                q_const.PORT_STATUS_DOWN,
-                                                host)
+        port_exists = bool(plugin.update_port_status(rpc_context, port_id,
+                                                     q_const.PORT_STATUS_DOWN,
+                                                     host))
 
         return {'device': device,
                 'exists': port_exists}
@@ -182,9 +182,9 @@ class RpcCallbacks(n_rpc.RpcCallback,
                       {'device': device, 'host': host})
             return
 
-        plugin.update_port_status(rpc_context, port_id,
-                                  q_const.PORT_STATUS_ACTIVE,
-                                  host)
+        port_id = plugin.update_port_status(rpc_context, port_id,
+                                            q_const.PORT_STATUS_ACTIVE,
+                                            host)
         l3plugin = manager.NeutronManager.get_service_plugins().get(
             service_constants.L3_ROUTER_NAT)
         if l3plugin: