diff --git a/tiramisu/config.py b/tiramisu/config.py
index 799954c..1a749e9 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -337,7 +337,7 @@ class Config(object):
                 else:
                     newowner = who 
         if type(child) != SymLinkOption:
-            if child.has_callback():
+            if child.has_callback() and who=='default':
                 raise TypeError("trying to set a value to an option "
                     "wich has a callback: {0}".format(name))
 #            if oldowner == who: