diff --git a/gestion/config/config.py b/gestion/config/config.py
index daad1c22..28466f73 100644
--- a/gestion/config/config.py
+++ b/gestion/config/config.py
@@ -8,6 +8,7 @@ import datetime
 # Fichier généré à partir de bcfg2
 from config_srv import adm_only, role
 
+gtfepoch = "19700101000000Z"
 ##### Gestion des câblages
 # Selon la date, on met :
 # -ann_scol : Année scolaire en cours
diff --git a/gestion/ldap_crans.py b/gestion/ldap_crans.py
index f18b5f99..1bf39a1a 100755
--- a/gestion/ldap_crans.py
+++ b/gestion/ldap_crans.py
@@ -1492,7 +1492,12 @@ class BaseProprietaire(BaseClasseCrans):
 
         # On récupère sur les factures l'ensemble de celles comportant une adhésion.
         adh_factures = self.factures_adh()
-        finAdh = max([0.0] + [fromGeneralizedTimeFormat(facture._data.get('finAdhesion', ["19700101000000Z"])[0]) for facture in adh_factures if facture.controle() != "FALSE" and facture.recuPaiement() is not None])
+        fgtf = lambda fac:fromGeneralizedTimeFormat(fac._data.get('finAdhesion', [config.gtfepoch])[0])
+        finAdh = max([0.0] + [fgtf(facture) for facture
+                              in adh_factures
+                              if facture.controle() != "FALSE"
+                                  and facture.recuPaiement() is not None
+                             ])
 
         if update == False:
             return finAdh
@@ -2382,7 +2387,12 @@ class Adherent(BaseProprietaire):
 
         # On récupère sur les factures l'ensemble de celles comportant une connexion.
         conn_factures = self.factures_conn()
-        finConn = max([0.0] + [fromGeneralizedTimeFormat(facture._data.get('finConnexion', ["19700101000000Z"])[0]) for facture in conn_factures if facture.controle() != "FALSE" and facture.recuPaiement() is not None])
+        fgtf = lambda fac:fromGeneralizedTimeFormat(fac._data.get('finConnexion', [config.gtfepoch])[0])
+        finConn = max([0.0] + [fgtf(facture) for facture
+                               in conn_factures
+                               if facture.controle() != "FALSE"
+                                   and facture.recuPaiement() is not None
+                              ])
 
         if mois is None:
             return finConn