diff --git a/machines/forms.py b/machines/forms.py
index 0c7d9cd4..ffdf4239 100644
--- a/machines/forms.py
+++ b/machines/forms.py
@@ -69,7 +69,8 @@ class AliasForm(ModelForm):
         fields = ['name','extension']
 
     def __init__(self, *args, **kwargs):
-        infra = kwargs.pop('infra')
+        if 'infra' in kwargs:
+            infra = kwargs.pop('infra')
         if 'name_user' in kwargs:
             name_user = kwargs.pop('name_user')
             nb_machine = kwargs.pop('nb_machine')
diff --git a/machines/views.py b/machines/views.py
index 381fe259..ab5bf567 100644
--- a/machines/views.py
+++ b/machines/views.py
@@ -101,32 +101,38 @@ def new_machine(request, userid):
     interface = AddInterfaceForm(request.POST or None, infra=request.user.has_perms(('infra',))) 
     nb_machine = Interface.objects.filter(machine__user=userid).count()
     domain = AliasForm(request.POST or None, infra=request.user.has_perms(('infra',)), name_user=user.surname, nb_machine=nb_machine)
-    if machine.is_valid() and interface.is_valid():
-        new_machine = machine.save(commit=False)
-        new_machine.user = user
-        new_interface = interface.save(commit=False)
-        new_domain = domain.save(commit=False)
-        if full_domain_validator(request, new_domain):
-            with transaction.atomic(), reversion.create_revision():
-                new_machine.save()
-                reversion.set_user(request.user)
-                reversion.set_comment("Création")
-            new_interface.machine = new_machine
-            if free_ip(new_interface.type.ip_type) and not new_interface.ipv4:
-                new_interface = assign_ipv4(new_interface)
-            elif not new_interface.ipv4:
-                messages.error(request, u"Il n'y a plus d'ip disponibles")
-            with transaction.atomic(), reversion.create_revision():
-                new_interface.save()
-                reversion.set_user(request.user)
-                reversion.set_comment("Création")
-            new_domain.interface_parent = new_interface
-            with transaction.atomic(), reversion.create_revision():
-                new_domain.save()
-                reversion.set_user(request.user)
-                reversion.set_comment("Création")
-            messages.success(request, "La machine a été crée")
-            return redirect("/users/profil/" + user)
+    try:
+         if machine.is_valid() and interface.is_valid() and domain.is_valid():
+            new_machine = machine.save(commit=False)
+            new_machine.user = user
+            if len(interface.cleaned_data['mac_address']) != 12:
+                messages.error(request, u"Adresse mac trop courte")
+                return form({'machineform': machine, 'interfaceform': interface, 'domainform': domain}, 'machines/machine.html', request)
+            new_interface = interface.save(commit=False)
+            new_domain = domain.save(commit=False)
+            if full_domain_validator(request, new_domain):
+                with transaction.atomic(), reversion.create_revision():
+                    new_machine.save()
+                    reversion.set_user(request.user)
+                    reversion.set_comment("Création")
+                new_interface.machine = new_machine
+                if free_ip(new_interface.type.ip_type) and not new_interface.ipv4:
+                    new_interface = assign_ipv4(new_interface)
+                elif not new_interface.ipv4:
+                    messages.error(request, u"Il n'y a plus d'ip disponibles")
+                with transaction.atomic(), reversion.create_revision():
+                    new_interface.save()
+                    reversion.set_user(request.user)
+                    reversion.set_comment("Création")
+                new_domain.interface_parent = new_interface
+                with transaction.atomic(), reversion.create_revision():
+                    new_domain.save()
+                    reversion.set_user(request.user)
+                    reversion.set_comment("Création")
+                messages.success(request, "La machine a été crée")
+                return redirect("/users/profil/" + str(user.id))
+    except TypeError:
+        messages.error(request, u"Adresse mac invalide")
     return form({'machineform': machine, 'interfaceform': interface, 'domainform': domain}, 'machines/machine.html', request)
 
 @login_required