diff --git a/attributs.py b/attributs.py
index 04d8155..5a6d8b8 100644
--- a/attributs.py
+++ b/attributs.py
@@ -1006,6 +1006,14 @@ class portUDPin(portAttr):
 class exempt(Attr):
     legend = u"Exemption vers une IP"
     ldap_name = "exempt"
+    python_type = netaddr.IPNetwork
+
+    def parse_value(self, net):
+        self.value = self.python_type(net)
+
+    def __unicode__(self):
+        return unicode(self.value)
+
 
 @crans_attribute
 class nombrePrises(intAttr):