diff -r e0ba9bd8f739 trytond/model/modelstorage.py
--- a/trytond/trytond/model/modelstorage.py	Wed Oct 11 10:36:36 2017 +0200
+++ b/trytond/trytond/model/modelstorage.py	Wed Oct 11 11:04:16 2017 +0200
@@ -1344,8 +1344,19 @@
                     ids.append(value)
                     return Model(value, **kwargs)
                 elif field._type in ('one2many', 'many2many'):
-                    ids.extend(int(x) for x in value)
-                    return tuple(Model(id, **kwargs) for id in value)
+                    models = []
+                    for x in value:
+                        if isinstance(x, dict):
+                            id = int(x['id'])
+                            data = x.copy()
+                            del data['id']
+                            data.update(kwargs)
+                        else:
+                            id = int(x)
+                            data = kwargs
+                        ids.append(id)
+                        models.append(Model(id, **data))
+                    return tuple(models)

         model2ids = {}
         model2cache = {}