diff --git a/objets.py b/objets.py
index cc7494e..0e95dd8 100644
--- a/objets.py
+++ b/objets.py
@@ -969,11 +969,14 @@ class proprio(CransLdapObject):
             self['mail'] = [login + u"@crans.org"]
             calias = crans_utils.strip_spaces(fn) + u'.' + crans_utils.strip_spaces(ln) + '@crans.org'
             if crans_utils.mailexist(calias):
-                calias = login
+                calias = login + u'@crans.org'
+                if crans_utils.mailexist(calias):
+                    raise ValueError('Creation impossible, Alias canonique déjà pris, merci de choisir un autre login')
             self['canonicalAlias'] = [calias]
             self['cn'] = [fn + u' ' + ln]
             self['loginShell'] = [unicode(shell)]
-            self['userPassword'] = [unicode(hash_pass)]
+            if hash_pass:
+                self['userPassword'] = [unicode(hash_pass)]
             self["solde"] = 0.0
 
             if uidNumber: