diff --git a/openerp/addons/test_new_api/tests/test_onchange.py b/openerp/addons/test_new_api/tests/test_onchange.py
index e9b7e1f83aa..3d0745a5f8b 100644
--- a/openerp/addons/test_new_api/tests/test_onchange.py
+++ b/openerp/addons/test_new_api/tests/test_onchange.py
@@ -146,8 +146,6 @@ class TestOnChange(common.TransactionCase):
             }),
             (1, message.id, {
                 'name': "[%s] %s" % ("Foo", USER.name),
-                # Note: size is computed because it was not provided beforehand
-                'size': len(BODY),
             }),
         ])
 
diff --git a/openerp/models.py b/openerp/models.py
index 3a8cb88423e..7dd628054a1 100644
--- a/openerp/models.py
+++ b/openerp/models.py
@@ -5787,6 +5787,11 @@ class BaseModel(object):
             # attach `self` with a different context (for cache consistency)
             record._origin = self.with_context(__onchange=True)
 
+        # load fields on secondary records, to avoid false changes
+        with env.do_in_onchange():
+            for field_seq in secondary:
+                record.mapped(field_seq)
+
         # determine which field(s) should be triggered an onchange
         todo = list(names) or list(values)
         done = set()