diff --git a/tempest/lib/services/clients.py b/tempest/lib/services/clients.py
index 0e8e3c6..e5497d2 100644
--- a/tempest/lib/services/clients.py
+++ b/tempest/lib/services/clients.py
@@ -373,7 +373,7 @@
                 except Exception:
                     LOG.exception(
                         'Failed to register service client from plugin %s '
-                        'with parameters %s' % (plugin, service_client))
+                        'with parameters %s', plugin, service_client)
                     raise
 
     def register_service_client_module(self, name, service_version,