diff --git a/gestion/ldap_crans.py b/gestion/ldap_crans.py
index a2f0a605..976996ab 100755
--- a/gestion/ldap_crans.py
+++ b/gestion/ldap_crans.py
@@ -2149,9 +2149,10 @@ class machine(base_classes_crans):
         
         # Attribution de la prise
         new=preattr(new)[1]
-        if new == 'N/A':
-            self._set('prise',[])
-            self._data.pop('prise')
+        if new == 'N/A' :
+            if self._data.has_key('prise') :
+                self._set('prise',[])
+                self._data.pop('prise')
             return
 
         if not sre.match('^[a-cg-jmp][0-6][0-5][0-9]$',new.lower()):