diff --git a/tempest/config.py b/tempest/config.py
index 14a6ad2..2a8d93f 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -1384,7 +1384,8 @@
             _CONF([], project='tempest')
 
         logging_cfg_path = "%s/logging.conf" % os.path.dirname(path)
-        if (not hasattr(_CONF, 'log_config_append') and
+        if ((not hasattr(_CONF, 'log_config_append') or
+            _CONF.log_config_append is None) and
             os.path.isfile(logging_cfg_path)):
             # if logging conf is in place we need to set log_config_append
             _CONF.log_config_append = logging_cfg_path