diff --git a/openerp/addons/base/ir/osv_memory_autovacuum.py b/openerp/addons/base/ir/osv_memory_autovacuum.py
index 1b3ca507eb8..b5224c0e7de 100644
--- a/openerp/addons/base/ir/osv_memory_autovacuum.py
+++ b/openerp/addons/base/ir/osv_memory_autovacuum.py
@@ -28,7 +28,7 @@ class osv_memory_autovacuum(openerp.osv.osv.osv_memory):
     def power_on(self, cr, uid, context=None):
         for model in self.pool.models.values():
             if model.is_transient():
-                model._transient_vacuum(cr, uid)
+                model._transient_vacuum(cr, uid, force=True)
         return True