diff --git a/machines/forms.py b/machines/forms.py
index d9e656be..89f5f5f8 100644
--- a/machines/forms.py
+++ b/machines/forms.py
@@ -32,6 +32,12 @@ class EditInterfaceForm(ModelForm):
         self.fields['type'].label = 'Type de machine'
         self.fields['type'].empty_label = "Séléctionner un type de machine"
 
+    def clean(self):
+        data = super(EditInterfaceForm, self).clean()
+        mac = str(self.data['mac_address'])
+        if len(''.join(mac.replace("-",":").split(":"))) != 12:
+            self.add_error('mac_address', "Format de la mac incorrect")
+
 class AddInterfaceForm(EditInterfaceForm):
     class Meta(EditInterfaceForm.Meta):
         fields = ['ipv4','mac_address','type','details']
diff --git a/machines/views.py b/machines/views.py
index 9212499c..9bd66628 100644
--- a/machines/views.py
+++ b/machines/views.py
@@ -102,12 +102,9 @@ def new_machine(request, userid):
     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)
     try:
-         if machine.is_valid() and interface.is_valid() and domain.is_valid():
+        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 de taille incorrecte")
-                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):
@@ -156,9 +153,6 @@ def edit_interface(request, interfaceid):
         if machine_form.is_valid() and interface_form.is_valid() and domain_form.is_valid():
             new_interface = interface_form.save(commit=False)
             new_machine = machine_form.save(commit=False)
-            if len(interface_form.cleaned_data['mac_address']) != 12:
-                messages.error(request, u"Adresse mac de taille incorrecte")
-                return form({'machineform': machine_form, 'interfaceform': interface_form, 'domainform': domain_form}, 'machines/machine.html', request)
             new_domain = domain_form.save(commit=False)
             if full_domain_validator(request, new_domain):
                 with transaction.atomic(), reversion.create_revision():
@@ -219,9 +213,6 @@ def new_interface(request, machineid):
     try:
         if interface_form.is_valid() and domain_form.is_valid():
             new_interface = interface_form.save(commit=False)
-            if len(interface_form.cleaned_data['mac_address']) != 12:
-                messages.error(request, u"Adresse mac de taille incorrecte")
-                return form({'machineform': machine_form, 'interfaceform': interface_form, 'domainform': domain_form}, 'machines/machine.html', request)
             new_interface.machine = machine
             new_domain = domain_form.save(commit=False)
             if full_domain_validator(request, new_domain):