diff --git a/gestioncof/forms.py b/gestioncof/forms.py
index 07b7cd89..e7672c8f 100644
--- a/gestioncof/forms.py
+++ b/gestioncof/forms.py
@@ -200,11 +200,11 @@ class UserProfileForm(forms.ModelForm):
 
 class RegistrationUserForm(forms.ModelForm):
     def __init__(self, *args, **kw):
-        new_user = kw.get('instance') is None
         super(RegistrationUserForm, self).__init__(*args, **kw)
         self.fields['username'].help_text = ""
-        if new_user:
-            self.fields['username'].validators = [MinLengthValidator(9)]
+
+    def force_long_username(self):
+        self.fields['username'].validators = [MinLengthValidator(9)]
 
     class Meta:
         model = User
diff --git a/gestioncof/views.py b/gestioncof/views.py
index 5b0cf7ec..a10f1867 100644
--- a/gestioncof/views.py
+++ b/gestioncof/views.py
@@ -364,6 +364,7 @@ def registration_form2(request, login_clipper=None, username=None):
     elif not login_clipper:
         # new user
         user_form = RegistrationPassUserForm()
+        user_form.force_long_username()
         profile_form = RegistrationProfileForm()
         event_formset = EventFormset(events=events, prefix='events')
     return render(request, "registration_form.html",
@@ -405,7 +406,9 @@ def registration(request):
                     clipper = Clipper.objects.get(username=username)
                     login_clipper = clipper.username
                 except Clipper.DoesNotExist:
-                    pass
+                    user_form.force_long_username()
+        else:
+            user_form.force_long_username()
 
         # -----
         # Validation des formulaires