diff --git a/tcp_tests/settings.py b/tcp_tests/settings.py
index 34103a1..fcbe1a9 100644
--- a/tcp_tests/settings.py
+++ b/tcp_tests/settings.py
@@ -34,7 +34,8 @@
 SHUTDOWN_ENV_ON_TEARDOWN = get_var_as_bool('SHUTDOWN_ENV_ON_TEARDOWN', True)
 
 LAB_CONFIG_NAME = os.environ.get('LAB_CONFIG_NAME', 'mk22-lab-basic')
-DOMAIN_NAME = os.environ.get('DOMAIN_NAME', LAB_CONFIG_NAME) + '.local'
+DOMAIN_NAME = os.environ.get('DOMAIN_NAME',
+                             '{}.local'.format(LAB_CONFIG_NAME))
 # LAB_CONFIGS_NAME = os.environ.get('LAB_NAME', 'mk22-lab-advanced')
 
 SSH_LOGIN = os.environ.get('SSH_LOGIN', 'root')