diff --git a/frappe/model/base_document.py b/frappe/model/base_document.py
index 78ab0fbdad..4f49baa532 100644
--- a/frappe/model/base_document.py
+++ b/frappe/model/base_document.py
@@ -128,7 +128,8 @@ class BaseDocument:
 			"doctype",
 			"meta",
 			"flags",
-			"parent_doc",
+			"_weakref",
+			"_parent_doc",
 			"_table_fields",
 			"_valid_columns",
 			"_doc_before_save",