diff --git a/tiramisu/config.py b/tiramisu/config.py
index bb284d0..8356aaa 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -214,10 +214,11 @@ class SubConfig(object):
     def __getattr__(self, name):
         return self.getattr(name)
 
-    def _getattr(self, name):
+    def _getattr(self, name, force_permissive=False, force_properties=None,
+                 validate=True):
         """use getattr instead of _getattr
         """
-        return self.getattr(name)
+        return self.getattr(name, force_permissive, force_properties, validate)
 
     def getattr(self, name, force_permissive=False, force_properties=None,
                 validate=True):