diff --git a/openerp/models.py b/openerp/models.py
index 018af585e2c..eaf643e7889 100644
--- a/openerp/models.py
+++ b/openerp/models.py
@@ -246,6 +246,9 @@ class NewId(object):
 IdType = (int, long, basestring, NewId)
 
 
+# maximum number of prefetched records
+PREFETCH_MAX = 200
+
 # special columns automatically created by the ORM
 LOG_ACCESS_COLUMNS = ['create_uid', 'create_date', 'write_uid', 'write_date']
 MAGIC_COLUMNS = ['id'] + LOG_ACCESS_COLUMNS
@@ -3137,6 +3140,9 @@ class BaseModel(object):
         # fetch the records of this model without field_name in their cache
         records = self._in_cache_without(field)
 
+        if len(records) > PREFETCH_MAX:
+            records = records[:PREFETCH_MAX] | self
+
         # by default, simply fetch field
         fnames = {field.name}