diff --git a/machines/views.py b/machines/views.py
index 059d938b..9883f011 100644
--- a/machines/views.py
+++ b/machines/views.py
@@ -90,7 +90,7 @@ def new_machine(request, userid):
     machine = NewMachineForm(request.POST or None)
     interface = AddInterfaceForm(request.POST or None, infra=request.user.has_perms(('infra',))) 
     nb_machine = Interface.objects.filter(machine__user=userid).count()
-    domain = DomainForm(request.POST or None, name_user=user.surname, nb_machine=nb_machine)
+    domain = DomainForm(request.POST or None, name_user=user.pseudo.replace('_','-'), nb_machine=nb_machine)
     if machine.is_valid() and interface.is_valid():
         new_machine = machine.save(commit=False)
         new_machine.user = user
diff --git a/users/models.py b/users/models.py
index 472e02ba..41eb969a 100644
--- a/users/models.py
+++ b/users/models.py
@@ -58,7 +58,7 @@ def remove_user_room(room):
 
 def linux_user_check(login):
     """ Validation du pseudo pour respecter les contraintes unix"""
-    UNIX_LOGIN_PATTERN = re.compile("^[a-zA-Z0-9_-]*[$]?$")
+    UNIX_LOGIN_PATTERN = re.compile("^[a-zA-Z0-9-]*[$]?$")
     return UNIX_LOGIN_PATTERN.match(login)
 
 
@@ -111,7 +111,7 @@ class UserManager(BaseUserManager):
             raise ValueError('Users must have an username')
 
         if not linux_user_check(pseudo):
-            raise ValueError('Username shall only contain [a-z0-9_-]')
+            raise ValueError('Username shall only contain [a-z0-9-]')
 
         user = self.model(
             pseudo=pseudo,