diff --git a/gestion/ldap_crans.py b/gestion/ldap_crans.py
index 99b193c0..b63a8101 100644
--- a/gestion/ldap_crans.py
+++ b/gestion/ldap_crans.py
@@ -2182,7 +2182,7 @@ class Adherent(BaseProprietaire):
             random.shuffle(pool_uid)
             while len(pool_uid) > 0:
                 uidNumber = pool_uid.pop()  # On choisit une IP
-                if not self.exist('(uidNumber=%s)'):
+                if not self.exist('(uidNumber=%s)' % uidNumber):
                     # On a trouvé un uid libre
                     pool_uid.append(uidNumber)
                     break