diff --git a/ChangeLog b/ChangeLog
index 67fb6af..04b5161 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 Sun Apr 27 10:32:40 2014 +0200 Emmanuel Garette <egarette@cadoles.com>
 
+	* behavior change in ChoiceOption:
+	remove open_values, that no sens (no type validation is possible) if
+	you wan't something like open_values, please use a typed option and
+	add impl_(s|g)et_information to add proposed values and use it in your
+	code
 	* add dynamic ChoiceOption:
 	we can have dynamic ChoiceOption. Parameter values can be a function
 	and as callback, we can add values_params
diff --git a/test/test_config_api.py b/test/test_config_api.py
index 979a1e8..488e7b8 100644
--- a/test/test_config_api.py
+++ b/test/test_config_api.py
@@ -268,7 +268,6 @@ def test_impl_getpaths():
 def test_invalid_option():
     raises(TypeError, "ChoiceOption('a', '', [1, 2])")
     raises(TypeError, "ChoiceOption('a', '', 1)")
-    raises(TypeError, "ChoiceOption('a', '', (1,), open_values='string')")
     raises(ValueError, "ChoiceOption('a', '', (1,), 3)")
     raises(ValueError, "FloatOption('a', '', 'string')")
     raises(ValueError, "UnicodeOption('a', '', 1)")
diff --git a/tiramisu/option/option.py b/tiramisu/option/option.py
index 9aeb7d5..584d94b 100644
--- a/tiramisu/option/option.py
+++ b/tiramisu/option/option.py
@@ -41,7 +41,7 @@ class ChoiceOption(Option):
     def __init__(self, name, doc, values, default=None,
                  values_params=None, default_multi=None, requires=None,
                  multi=False, callback=None, callback_params=None,
-                 open_values=False, validator=None, validator_params=None,
+                 validator=None, validator_params=None,
                  properties=None, warnings_only=False):
         """
         :param values: is a list of values the option can possibly take
@@ -51,11 +51,7 @@ class ChoiceOption(Option):
         elif not isinstance(values, tuple):
             raise TypeError(_('values must be a tuple or a function for {0}'
                               ).format(name))
-        if open_values not in (True, False):
-            raise TypeError(_('open_values must be a boolean for '
-                            '{0}').format(name))
-        self._extra = {'_choice_open_values': open_values,
-                       '_choice_values': values,
+        self._extra = {'_choice_values': values,
                        '_choice_values_params': values_params}
         super(ChoiceOption, self).__init__(name, doc, default=default,
                                            default_multi=default_multi,
@@ -83,14 +79,10 @@ class ChoiceOption(Option):
                                     '').format(self.impl_getname()))
         return values
 
-    def impl_is_openvalues(self):
-        return self._extra['_choice_open_values']
-
     def _validate(self, value, context=None):
         try:
             values = self.impl_get_values(context)
-            if not self.impl_is_openvalues() and \
-                    not value in values:
+            if not value in values:
                 raise ValueError(_('value {0} is not permitted, '
                                  'only {1} is allowed'
                                  '').format(value,