diff --git a/openslides/participant/models.py b/openslides/participant/models.py
index f833f3bd7..850b23806 100644
--- a/openslides/participant/models.py
+++ b/openslides/participant/models.py
@@ -22,7 +22,7 @@ from openslides.utils.person.signals import receiv_persons
 from openslides.config.signals import default_config_value
 
 
-class OpenSlidesUser(models.Model, PersonMixin):
+class OpenSlidesUser(User, PersonMixin):
     person_prefix = 'openslides_user'
     GENDER_CHOICES = (
         ('male', _('Male')),
@@ -35,10 +35,10 @@ class OpenSlidesUser(models.Model, PersonMixin):
         ('guest', _('Guest')),
     )
 
-    user = models.OneToOneField(User, unique=True, editable=False)
+    user = models.OneToOneField(User, unique=True, editable=False, parent_link=True)
     category = models.CharField(
         max_length=100, null=True, blank=True, verbose_name=_("Category"),
-        help_text=_('Shown behind the name.'))
+        help_text=_('Will be shown behind the name.'))
     gender = models.CharField(
         max_length=50, choices=GENDER_CHOICES, blank=True,
         verbose_name=_("Gender"), help_text=_('Only for filter the userlist.'))
@@ -65,27 +65,6 @@ class OpenSlidesUser(models.Model, PersonMixin):
 
     name_surfix = property(get_name_surfix, set_name_surfix)
 
-    def get_first_name(self):
-        return self.user.first_name
-
-    def set_first_name(self, first_name):
-        self.user.first_name = first_name
-        self.save_user_object = True
-
-    first_name = property(get_first_name, set_first_name)
-
-    def get_full_name(self):
-        return "%s %s" % self.first_name, self.last_name
-
-    def get_last_name(self):
-        return self.user.last_name
-
-    def set_last_name(self, last_name):
-        self.user.last_name = last_name
-        self.save_user_object = True
-
-    last_name = property(get_last_name, set_last_name)
-
     def reset_password(self, password=None):
         """
         Reset the password for the user to his default-password.
@@ -95,12 +74,6 @@ class OpenSlidesUser(models.Model, PersonMixin):
         self.user.set_password(password)
         self.user.save()
 
-    def has_perm(self, perm):
-        return self.user.has_perm(perm)
-
-    def save_in_user_object(self, attribute, value):
-        self.save_in_user_object_dict[attribute] = value
-
     @models.permalink
     def get_absolute_url(self, link='edit'):
         """
@@ -120,12 +93,6 @@ class OpenSlidesUser(models.Model, PersonMixin):
             return u"%s (%s)" % (self.get_full_name(), self.name_surfix)
         return u"%s" % self.get_full_name()
 
-    def save(self, *args, **kwargs):
-        if self.save_user_object:
-            self.user.save()
-            self.save_user_object = False
-        super(OpenSlidesUser, self).save(*args, **kwargs)
-
     class Meta:
         # Rename permissions
         permissions = (
@@ -193,8 +160,10 @@ def default_config(sender, key, **kwargs):
 
 @receiver(signals.post_save, sender=User)
 def user_post_save(sender, instance, signal, *args, **kwargs):
-    # Creates OpenSlidesUser
-    openslidesuser, new = OpenSlidesUser.objects.get_or_create(user=instance)
+    try:
+        instance.openslidesuser
+    except OpenSlidesUser.DoesNotExist:
+        OpenSlidesUser(user=instance).save_base(raw=True)
 
 
 @receiver(signals.post_save, sender=Group)