diff --git a/neutron/agent/securitygroups_rpc.py b/neutron/agent/securitygroups_rpc.py
index 26bbbbf5763..2f2a8b386b5 100644
--- a/neutron/agent/securitygroups_rpc.py
+++ b/neutron/agent/securitygroups_rpc.py
@@ -104,11 +104,11 @@ class SecurityGroupAgentRpc(object):
             self.firewall = firewall_class(
                 integration_bridge=integration_bridge)
         except TypeError as e:
-            LOG.warning(_LW("Firewall driver {fw_driver} doesn't accept "
+            LOG.warning(_LW("Firewall driver %(fw_driver)s doesn't accept "
                             "integration_bridge parameter in __init__(): "
-                            "{err}"),
-                     fw_driver=firewall_driver,
-                     err=e)
+                            "%(err)s"),
+                        {'fw_driver': firewall_driver,
+                         'err': e})
             self.firewall = firewall_class()
         # The following flag will be set to true if port filter must not be
         # applied as soon as a rule or membership notification is received