diff --git a/src/m2ee/config.py b/src/m2ee/config.py
index dd5da95..920a7ff 100644
--- a/src/m2ee/config.py
+++ b/src/m2ee/config.py
@@ -32,7 +32,7 @@ def __init__(self, yaml_files=None):
         self._conf['mxruntime'].setdefault(
             'BasePath', self._conf['m2ee']['app_base'])
 
-        self._conf['mxruntime']['DTAPMode'] = 'P'
+        self._conf['mxruntime'].setdefault('DTAPMode', 'P')
 
         self._model_metadata = self._try_load_json(
             os.path.join(