diff --git a/gestion/ldap_crans.py b/gestion/ldap_crans.py
index 01ae272e..1fd2b6aa 100755
--- a/gestion/ldap_crans.py
+++ b/gestion/ldap_crans.py
@@ -760,7 +760,7 @@ class base_classes_crans(crans_ldap) :
 	    modif='inscription'
 	else :
             if "chbre" in self.modifs:
-                modif=filter(lambda x: x!="chbre", self.modifs)
+                modif= self.modifs.remove("chbre")
                 modif.append("chbre %s -> %s" % (self._init_data["chbre"][0],
                                                  self._data["chbre"][0]))
             else:
@@ -846,6 +846,8 @@ class base_classes_crans(crans_ldap) :
 	for m in self.modifs :
 	    if sre.match('blacklist_*',m) :
 		serv.append(m)
+	    elif m == 'chbre' and '????' in [ self._init_data.get("chbre",[])[0] , self._data.get("chbre",[])[0] ] :
+		serv.append('bl_chbre_invalide')
 	    else :
 		for s in annuaire_modif_service.get(m,[]) :
 		    if s not in serv :