diff --git a/tiramisu/config.py b/tiramisu/config.py
index 306f69b..4440459 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -393,6 +393,7 @@ class Config(SubConfig):
         :param kwargs: dict of name strings to values.
         """
         #opts, paths = self.cfgimpl_get_description()._cache_paths
+        #FIXME _validate pour apply_requires ?
         all_paths = [p.split(".") for p in self.getpaths(allpaths=True)]
         for key, value in kwargs.iteritems():
             key_p = key.split('.')
diff --git a/tiramisu/option.py b/tiramisu/option.py
index cedea5e..9bdd4a5 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -25,7 +25,7 @@ from copy import copy
 from types import FunctionType
 from tiramisu.error import (ConfigError, NotFoundError, ConflictConfigError,
                             RequiresError)
-from tiramisu.setting import groups, multitypes, apply_requires
+from tiramisu.setting import groups, multitypes
 
 name_regexp = re.compile(r'^\d+')
 
@@ -237,10 +237,10 @@ class Option(BaseInformation):
                             "config has been frozen".format(name))
 
         if setting.has_property('frozen') and setting.has_property('frozen',
-                                                                   self):
+                                                                   self, False):
             raise TypeError('cannot change the value to %s for '
                             'option %s this option is frozen' % (str(value), name))
-        apply_requires(self, config)
+        #apply_requires(self, config)
         config.cfgimpl_get_values()[self] = value
 
     def getkey(self, value):
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 9fc9a95..74022b3 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -83,7 +83,7 @@ class Values(object):
         else:
             set_mandatory = ('mandatory' in force_properties or
                              setting.has_property('mandatory'))
-        if setting.has_property('mandatory', opt) and set_mandatory:
+        if setting.has_property('mandatory', opt, False) and set_mandatory:
             if self._is_empty(opt, value) and opt.is_empty_by_default():
                 raise MandatoryError("option: {0} is mandatory "
                                      "and shall have a value".format(opt._name))
@@ -122,14 +122,14 @@ class Values(object):
         # options with callbacks
         value = self._get_value(opt)
         setting = self.context.cfgimpl_get_settings()
-        is_frozen = setting.has_property('frozen', opt)
+        is_frozen = setting.has_property('frozen', opt, False)
         if opt.has_callback():
             #if value is set and :
             # - not frozen
             # - frozen and not force_default_on_freeze
             if not self.is_default_owner(opt) and (
                     not is_frozen or (is_frozen and
-                                      not setting.has_property('force_default_on_freeze', opt))):
+                                      not setting.has_property('force_default_on_freeze', opt, False))):
                 return value
             value = self._getcallback_value(opt)
             if opt.is_multi():
@@ -140,7 +140,7 @@ class Values(object):
             #suppress value if already set
             self.reset(opt)
         # frozen and force default
-        elif is_frozen and setting.has_property('force_default_on_freeze', opt):
+        elif is_frozen and setting.has_property('force_default_on_freeze', opt, False):
             value = opt.getdefault()
             if opt.is_multi():
                 value = self.fill_multi(opt, value)