diff --git a/kfet/forms.py b/kfet/forms.py
index 7826cb41..64c39bb2 100644
--- a/kfet/forms.py
+++ b/kfet/forms.py
@@ -1,6 +1,7 @@
 from decimal import Decimal
 from django import forms
 from django.core.exceptions import ValidationError
+from django.core.validators import MinLengthValidator
 from django.contrib.auth.models import User, Group, Permission
 from django.contrib.contenttypes.models import ContentType
 from django.forms import modelformset_factory, inlineformset_factory
@@ -75,6 +76,12 @@ class CofRestrictForm(CofForm):
         fields = ['departement']
 
 class UserForm(forms.ModelForm):
+    def __init__(self, *args, **kwargs):
+        new_user = kwargs.get('instance') is None
+        super(UserForm, self).__init__(*args, **kwargs)
+        if new_user:
+            self.fields['username'].validators = [MinLengthValidator(9)]
+
     class Meta:
         model  = User
         fields = ['username', 'first_name', 'last_name', 'email']
diff --git a/kfet/views.py b/kfet/views.py
index d99d3262..844ed8ce 100644
--- a/kfet/views.py
+++ b/kfet/views.py
@@ -190,6 +190,8 @@ def account_create_ajax(request, username=None, login_clipper=None):
         user_form    = UserForm()
         cof_form     = CofForm()
         account_form = AccountNoTriForm()
+        cof_form.fields['login_clipper'].widget.attrs['readonly'] = True
+        cof_form.fields['is_cof'].widget.attrs['disabled'] = True
 
     return render(request, "kfet/account_create_form.html", {
             'account_form' : account_form,