diff --git a/openerp/fields.py b/openerp/fields.py
index b78f5b330d2..2688e7e56ca 100644
--- a/openerp/fields.py
+++ b/openerp/fields.py
@@ -1482,7 +1482,11 @@ class Many2one(_Relational):
             # many2one field value (id and name) depends on the current record's
             # access rights, and not the value's access rights.
             try:
-                return value.sudo().name_get()[0]
+                value_sudo = value.sudo()
+                # performance trick: make sure that all records of the same
+                # model as value in value.env will be prefetched in value_sudo.env
+                value_sudo.env.prefetch[value._name].update(value.env.prefetch[value._name])
+                return value_sudo.name_get()[0]
             except MissingError:
                 # Should not happen, unless the foreign key is missing.
                 return False