diff --git a/tiramisu/option/baseoption.py b/tiramisu/option/baseoption.py
index 89865ad..08027d5 100644
--- a/tiramisu/option/baseoption.py
+++ b/tiramisu/option/baseoption.py
@@ -173,7 +173,6 @@ class Base(object):
         """
         :add_value: add value as first argument for validator
         """
-
         is_multi = self.impl_is_dynoptiondescription() or self.impl_is_multi()
         func_args, func_kwargs, func_positional, func_keyword = self._get_function_args(calculator)
         calculator_args, calculator_kwargs = self._get_parameters_args(calculator_params, add_value)
@@ -279,11 +278,12 @@ class Base(object):
                                 self)
             callback_params = self._build_calculator_params(callback,
                                                             callback_params)
+            # first part is validator
             val = getattr(self, '_val_call', (None,))[0]
             if callback_params == {}:
                 val_call = (callback,)
             else:
-                val_call = tuple([callback, callback_params])
+                val_call = (callback, callback_params)
             self._val_call = (val, val_call)
 
     def impl_is_optiondescription(self):
diff --git a/tiramisu/option/choiceoption.py b/tiramisu/option/choiceoption.py
index fd348bd..5856c42 100644
--- a/tiramisu/option/choiceoption.py
+++ b/tiramisu/option/choiceoption.py
@@ -60,6 +60,10 @@ class ChoiceOption(Option):
                                 values_params,
                                 'values',
                                 self)
+            values_params = self._build_calculator_params(values,
+                                                          values_params)
+            if values_params != {}:
+                self._choice_values_params = values_params
         else:
             if values_params is not None:
                 raise ValueError(_('values is not a function, so values_params must be None'))
@@ -67,8 +71,6 @@ class ChoiceOption(Option):
                 raise TypeError(_('values must be a tuple or a function for {0}'
                                  ).format(name))
         self._choice_values = values
-        if values_params is not None:
-            self._choice_values_params = values_params
         super(ChoiceOption, self).__init__(name,
                                            doc,
                                            default=default,