diff --git a/neutron/agent/linux/external_process.py b/neutron/agent/linux/external_process.py
index f5bc1f89b0a..a00819ae45d 100644
--- a/neutron/agent/linux/external_process.py
+++ b/neutron/agent/linux/external_process.py
@@ -115,7 +115,7 @@ class ProcessManager(MonitoredProcess):
                 if sig == '9':
                     fileutils.delete_if_exists(self.get_pid_file_name())
         elif pid:
-            LOG.debug('%{service}s process for %(uuid)s pid %(pid)d is stale, '
+            LOG.debug('%(service)s process for %(uuid)s pid %(pid)d is stale, '
                       'ignoring signal %(signal)s',
                       {'service': self.service, 'uuid': self.uuid,
                        'pid': pid, 'signal': sig})