diff --git a/opennebula_api/models.py b/opennebula_api/models.py
index d584bf26..7042f3c0 100644
--- a/opennebula_api/models.py
+++ b/opennebula_api/models.py
@@ -150,7 +150,7 @@ class OpenNebulaManager():
                 oca.User.METHODS['allocate'], email,
                 password, 'core')
             logger.debug(
-                "User {0} does not exist. Created the user. User id = {1}",
+                "User {} does not exist. Created the user. User id = {}",
                 email,
                 opennebula_user
             )