diff --git a/mongoengine/base/document.py b/mongoengine/base/document.py
index 64bf24a4..f8dd8400 100644
--- a/mongoengine/base/document.py
+++ b/mongoengine/base/document.py
@@ -712,14 +712,6 @@ class BaseDocument(object):
                         del data[field.db_field]
                 except (AttributeError, ValueError), e:
                     errors_dict[field_name] = e
-            elif field.default:
-                default = field.default
-                if callable(default):
-                    default = default()
-                if isinstance(default, BaseDocument):
-                    changed_fields.append(field_name)
-                elif not only_fields or field_name in only_fields:
-                    changed_fields.append(field_name)
 
         if errors_dict:
             errors = "\n".join(["%s - %s" % (k, v)