diff --git a/tiramisu/setting.py b/tiramisu/setting.py
index 838cc01..95149c8 100644
--- a/tiramisu/setting.py
+++ b/tiramisu/setting.py
@@ -314,13 +314,13 @@ class Settings(object):
                 raise PropertiesOptionError(_('cannot change the value for '
                                               'option {0} this option is'
                                               ' frozen').format(
-                                              opt_or_descr._name),
-                                              props)
+                                                  opt_or_descr._name),
+                                            props)
             else:
                 raise PropertiesOptionError(_("trying to access to an option "
                                               "named: {0} with properties {1}"
                                               "").format(opt_or_descr._name,
-                                              str(props)), props)
+                                                         str(props)), props)
 
     #FIXME should be setpermissive
     def set_permissive(self, permissive, opt=None):
@@ -372,12 +372,13 @@ class Settings(object):
             matches = False
             for require in requires:
                 option, expected, action, inverse, \
-                transitive, same_action = require
+                    transitive, same_action = require
                 path = descr.impl_get_path_by_opt(option)
                 if path == optpath or path.startswith(optpath + '.'):
                     raise RequirementError(_("malformed requirements "
-                          "imbrication detected for option: '{0}' "
-                          "with requirement on: '{1}'").format(optpath, path))
+                                             "imbrication detected for option:"
+                                             " '{0}' with requirement on: "
+                                             "'{1}'").format(optpath, path))
                 try:
                     value = self.context._getattr(path, force_permissive=True)
                 except PropertiesOptionError, err:
@@ -398,8 +399,8 @@ class Settings(object):
                     raise AttributeError(_("required option not found: "
                                            "{0}").format(path))
                 if (not inverse and
-                    value in expected or
-                    inverse and value not in expected):
+                        value in expected or
+                        inverse and value not in expected):
                     matches = True
                     setting.append(action)
                     ## the calculation cannot be carried out