diff --git a/neutron/agent/l2/extensions/qos.py b/neutron/agent/l2/extensions/qos.py
index 4bb1773b386..e509ec34745 100644
--- a/neutron/agent/l2/extensions/qos.py
+++ b/neutron/agent/l2/extensions/qos.py
@@ -16,7 +16,6 @@
 import abc
 import collections
 
-from neutron_lib import exceptions
 from oslo_concurrency import lockutils
 from oslo_log import log as logging
 import six
@@ -168,7 +167,8 @@ class PortPolicyMap(object):
                     if not port_dict:
                         self._clean_policy_info(qos_policy_id)
                     return
-        raise exceptions.PortNotFound(port_id=port['port_id'])
+        LOG.debug("QoS extension did not have information on port %s",
+                  port_id)
 
     def _clean_policy_info(self, qos_policy_id):
         del self.qos_policy_ports[qos_policy_id]
@@ -274,10 +274,5 @@ class QosAgentExtension(l2_agent_extension.L2AgentExtension):
             self.policy_map.update_policy(qos_policy)
 
     def _process_reset_port(self, port):
-        try:
-            self.policy_map.clean_by_port(port)
-            self.qos_driver.delete(port)
-        except exceptions.PortNotFound:
-            LOG.info(_LI("QoS extension did have no information about the "
-                         "port %s that we were trying to reset"),
-                     port['port_id'])
+        self.policy_map.clean_by_port(port)
+        self.qos_driver.delete(port)
diff --git a/neutron/tests/unit/agent/l2/extensions/test_qos.py b/neutron/tests/unit/agent/l2/extensions/test_qos.py
index 30bb643a365..2c7c2e80f02 100644
--- a/neutron/tests/unit/agent/l2/extensions/test_qos.py
+++ b/neutron/tests/unit/agent/l2/extensions/test_qos.py
@@ -15,7 +15,6 @@
 
 import mock
 from neutron_lib import context
-from neutron_lib import exceptions
 from oslo_utils import uuidutils
 
 from neutron.agent.l2.extensions import qos
@@ -223,7 +222,7 @@ class QosExtensionRpcTestCase(QosExtensionBaseTestCase):
     def test_delete_unknown_port(self):
         port = self._create_test_port_dict()
         self.qos_ext.delete_port(self.context, port)
-        self.assertFalse(self.qos_ext.qos_driver.delete.called)
+        self.assertTrue(self.qos_ext.qos_driver.delete.called)
         self.assertIsNone(self.qos_ext.policy_map.get_port_policy(port))
 
     def test__handle_notification_ignores_all_event_types_except_updated(self):
@@ -415,9 +414,11 @@ class PortPolicyMapTestCase(base.BaseTestCase):
         self.assertNotIn(TEST_PORT['port_id'], self.policy_map.port_policies)
         self.assertIn(TEST_POLICY2.id, self.policy_map.known_policies)
 
-    def test_clean_by_port_raises_exception_for_unknown_port(self):
-        self.assertRaises(exceptions.PortNotFound,
-                          self.policy_map.clean_by_port, TEST_PORT)
+    def test_clean_by_port_for_unknown_port(self):
+        self.policy_map._clean_policy_info = mock.Mock()
+        self.policy_map.clean_by_port(TEST_PORT)
+
+        self.policy_map._clean_policy_info.assert_not_called()
 
     def test_has_policy_changed(self):
         self._set_ports()