diff --git a/tiramisu/option/option.py b/tiramisu/option/option.py
index 39fd1f2..d28092f 100644
--- a/tiramisu/option/option.py
+++ b/tiramisu/option/option.py
@@ -267,11 +267,11 @@ class Option(BaseOption):
                         else:
                             raise err
         try:
+            err_index = None
             if isinstance(value, Calculation):
                 pass
             elif not self.impl_is_multi():
                 val = value
-                err_index = None
                 do_validation(val, None)
             elif self.impl_is_submulti():
                 if not isinstance(value, list):
@@ -297,7 +297,7 @@ class Option(BaseOption):
                     do_validation(val,
                                   err_index)
         except ValueError as err:
-            raise ValueOptionError(val,
+            raise ValueOptionError(value,
                                    self._display_name,
                                    option_bag.ori_option,
                                    '{0}'.format(err),
@@ -407,10 +407,10 @@ class Option(BaseOption):
                 if self.impl_is_submulti():
                     if not isinstance(value, list):
                         raise ValueError(_('which must be a list'))
-                    _is_not_unique(value, option_bag)
                     for val in value:
                         await do_validation(val,
                                             force_index)
+                    _is_not_unique(value, option_bag)
                 else:
                     await do_validation(val,
                                         force_index)
@@ -420,7 +420,6 @@ class Option(BaseOption):
                 raise ValueError(_('which must be a list'))
             elif self.impl_is_submulti():
                 for err_index, lval in enumerate(value):
-                    _is_not_unique(lval, option_bag)
                     if isinstance(lval, Calculation):
                         continue
                     if not isinstance(lval, list):
@@ -429,12 +428,13 @@ class Option(BaseOption):
                     for val in lval:
                         await do_validation(val,
                                             err_index)
+                    _is_not_unique(lval, option_bag)
             else:
-                _is_not_unique(value, option_bag)
                 # FIXME subtimal, not several time is whole=True!
                 for err_index, val in enumerate(value):
                     await do_validation(val,
                                         err_index)
+                _is_not_unique(value, option_bag)
         except ValueError as err:
             if config_bag is undefined or \
                     'demoting_error_warning' not in config_bag.properties: