diff --git a/trytond/model/modelsql.py b/trytond/model/modelsql.py
index 2ebbd93b8c..be6155e00d 100644
--- a/trytond/model/modelsql.py
+++ b/trytond/model/modelsql.py
@@ -1196,9 +1196,9 @@ class ModelSQL(ModelStorage):
         cache.setdefault(self._name, {})
         for data in datas:
             for i in data.keys():
-                if i in ('_timestamp', '_datetime'):
+                if i.strip('"') in ('_timestamp', '_datetime'):
                     continue
-                field = self._columns[i]
+                field = self._columns[i.strip('"')]
                 if field._type in ('many2one',):
                     if field.model_name not in self.pool.object_name_list():
                         del data[i]