diff --git a/tests/test_leadership.py b/tests/test_leadership.py
index 8f119b0..f41a548 100644
--- a/tests/test_leadership.py
+++ b/tests/test_leadership.py
@@ -200,6 +200,24 @@ def test_groups_is_leader(config_type):
 #    assert not list_sessions()
 
 
+def test_leader_follower_index():
+    ip = StrOption('ip', "", ['val1', 'val2'], multi=True)
+    netmask = StrOption('netmask', "", multi=True, default_multi='value')
+    interface1 = Leadership('leadership', '', [ip, netmask])
+    od1 = OptionDescription('od', '', [interface1])
+    cfg = Config(od1)
+    assert cfg.option('leadership.ip').value.get() == ['val1', 'val2']
+    with pytest.raises(ConfigError):
+        cfg.option('leadership.ip').index(0)
+    follower = cfg.option('leadership.netmask')
+    with pytest.raises(ConfigError):
+        follower.value.get()
+    assert follower.index(0).value.get() == 'value'
+    assert follower.index(0).index(None).index() is None
+    with pytest.raises(ConfigError):
+        follower.index(0).index(None).value.get()
+
+
 def test_leader_list(config_type):
     ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", ['val1'], multi=True)
     netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True, default_multi='value')
diff --git a/tests/test_option_owner.py b/tests/test_option_owner.py
index 6eeccf4..8075aff 100644
--- a/tests/test_option_owner.py
+++ b/tests/test_option_owner.py
@@ -64,15 +64,17 @@ def test_hidden_owner():
     od1 = OptionDescription('tiramisu', '', [gcdummy])
     cfg = Config(od1)
     cfg.property.read_write()
-    #with pytest.raises(PropertiesOptionError):
-    #    cfg.forcepermissive.option('dummy').owner.get()
-    #with pytest.raises(PropertiesOptionError):
-    #    cfg.option('dummy').owner.isdefault()
-    #with pytest.raises(PropertiesOptionError):
-    #    cfg.forcepermissive.option('dummy').owner.isdefault()
+    with pytest.raises(PropertiesOptionError):
+        cfg.option('dummy').value.get()
+    with pytest.raises(PropertiesOptionError):
+        cfg.option('dummy').owner.isdefault()
     cfg.permissive.add('hidden')
     cfg.forcepermissive.option('dummy').value.get()
     cfg.forcepermissive.option('dummy').owner.isdefault()
+    option = cfg.option("dummy")
+    option.forcepermissive()
+    option.value.get()
+    option.owner.isdefault()
 #    assert not list_sessions()
 
 
diff --git a/tiramisu/api.py b/tiramisu/api.py
index 1fefb10..f5c0f35 100644
--- a/tiramisu/api.py
+++ b/tiramisu/api.py
@@ -253,11 +253,12 @@ class CommonTiramisuOption(CommonTiramisu):
         path: str,
         index: Optional[int],
         config_bag: ConfigBag,
+        subconfig: Optional[SubConfig]=None,
     ) -> None:
         self._path = path
         self._index = index
         self._config_bag = config_bag
-        self._subconfig = None
+        self._subconfig = subconfig
         self._set_subconfig()
 
 
@@ -662,11 +663,16 @@ class _TiramisuOptionOption(_TiramisuOptionOptionDescription):
             return r"^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$"
 
     @option_type(["option", "with_or_without_index", "symlink"])
-    def index(self, index=None):
+    def index(self, index=undefined):
         """Get index of option"""
-        if index is None:
+        if index is undefined:
             return self._subconfig.index
-        return TiramisuOption(self._path, index, self._config_bag)
+        subconfig = self._subconfig.parent.get_child(
+            self._subconfig.option,
+            index,
+            True,
+        )
+        return TiramisuOption(self._path, index, self._config_bag, subconfig=subconfig)
 
     @option_type(["symlink", "optiondescription", "allow_dynoption"])
     def option(self, *args, **kwargs):
@@ -1062,11 +1068,6 @@ class TiramisuOptionValue(CommonTiramisuOption, _TiramisuODGet):
                 self.__class__.__name__, func.__name__
             )
             raise ConfigError(msg)
-        if (
-            "force_store_value" in self._subconfig.properties
-            and "force_store_value" in self._config_bag.properties
-        ):
-            return self._get(self._subconfig)
         return self._config_bag.context.get_values().get_default_value(self._subconfig)
 
     @option_type(
@@ -1238,6 +1239,7 @@ class TiramisuOption(
                 self._path,
                 self._index,
                 self._config_bag,
+                self._subconfig,
             )
         raise ConfigError(
             _("please specify a valid sub function ({0}.{1}) for {2}").format(
@@ -1317,6 +1319,10 @@ class TiramisuOption(
             self._load_dict()
         return self._tiramisu_dict.set_updates(body)
 
+    def forcepermissive(self):
+        self._set_subconfig()
+        self._subconfig.config_bag.set_permissive()
+
 
 class TiramisuContextInformation(TiramisuConfig):
     """Manage config informations"""
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 0e79db8..440c0e7 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -318,28 +318,31 @@ class Values:
         elif isinstance(value, list):
             # copy
             value = value.copy()
-        elif isinstance(value, Calculation):
-            value, _has_calculation = get_calculated_value(
-                subconfig,
-                value,
-            )
         self._setvalue(
             subconfig,
             ori_value,
             owner,
         )
         if (
-            "force_store_value" in self_properties
+            "force_store_value" in setting_properties
             and subconfig.option.impl_is_leader()
         ):
             leader = subconfig.option.impl_get_leadership()
             parent = subconfig.parent
-            parent._length = len(value)
-            leader.follower_force_store_value(
-                value,
-                parent,
-                owners.forced,
-            )
+            try:
+                if isinstance(value, Calculation):
+                    value, has_calculation = get_calculated_value(
+                        subconfig,
+                        value,
+                    )
+                parent._length = len(value)
+                leader.follower_force_store_value(
+                    value,
+                    parent,
+                    owners.forced,
+                )
+            except:
+                pass
         validator = (
             "validator" in setting_properties
             and "validator" in self_properties