diff --git a/tiramisu/option/masterslave.py b/tiramisu/option/masterslave.py
index 972c4ef..ac038ea 100644
--- a/tiramisu/option/masterslave.py
+++ b/tiramisu/option/masterslave.py
@@ -117,30 +117,32 @@ class MasterSlaves(object):
     def getitem(self, values, opt, path, validate, force_permissive,
                 trusted_cached_properties, validate_properties, session,
                 slave_path=undefined, slave_value=undefined,
-                setting_properties=undefined, self_properties=undefined, index=None):
+                setting_properties=undefined, self_properties=undefined, index=None,
+                check_frozen=False):
         if self.is_master(opt):
             return self._getmaster(values, opt, path, validate,
                                    force_permissive,
                                    validate_properties, slave_path,
                                    slave_value, self_properties, index,
-                                   setting_properties, session)
+                                   setting_properties, session, check_frozen)
         else:
             return self._getslave(values, opt, path, validate,
                                   force_permissive, trusted_cached_properties,
                                   validate_properties, setting_properties,
                                   self_properties, index,
-                                  session)
+                                  session, check_frozen)
 
     def _getmaster(self, values, opt, path, validate, force_permissive,
                    validate_properties, c_slave_path,
                    c_slave_value, self_properties, index,
-                   setting_properties, session):
+                   setting_properties, session, check_frozen):
         value = values._get_cached_value(opt, path=path, validate=validate,
                                          force_permissive=force_permissive,
                                          validate_properties=validate_properties,
                                          self_properties=self_properties,
                                          from_masterslave=True, index=index,
-                                         setting_properties=setting_properties)
+                                         setting_properties=setting_properties,
+                                         check_frozen=check_frozen)
         if isinstance(value, Exception):
             return value
         if index is None and validate is True:
@@ -153,7 +155,7 @@ class MasterSlaves(object):
 
     def _getslave(self, values, opt, path, validate, force_permissive,
                   trusted_cached_properties, validate_properties, setting_properties,
-                  self_properties, index, session):
+                  self_properties, index, session, check_frozen):
         """
         if master has length 0:
             return []
@@ -215,7 +217,8 @@ class MasterSlaves(object):
                                              #self_properties=self_properties,
                                              setting_properties=setting_properties,
                                              masterlen=masterlen,
-                                             from_masterslave=True)
+                                             from_masterslave=True,
+                                             check_frozen=check_frozen)
             if isinstance(value, Exception):
                 if isinstance(value, PropertiesOptionError):
                     err = value
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 726ca4c..4faa0ef 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -282,7 +282,8 @@ class Values(object):
                                                        session,
                                                        setting_properties=setting_properties,
                                                        index=index,
-                                                       self_properties=self_properties)
+                                                       self_properties=self_properties,
+                                                       check_frozen=check_frozen)
         else:
             val = self._get_validated_value(opt, path, validate,
                                             force_permissive,