diff --git a/neps/nep-0568.md b/neps/nep-0568.md
index 6e4d9dd93..ebdcebc81 100644
--- a/neps/nep-0568.md
+++ b/neps/nep-0568.md
@@ -509,10 +509,14 @@ Mappings in `DBCol::ShardUIdMapping` persist as long as any descendant relies on
 
 ```rust
 fn set_shard_uid_mapping(&mut self, child_shard_uid: ShardUId, parent_shard_uid: ShardUId) {
+    let mapped_parent_shard_uid = store
+          .get_ser::<ShardUId>(DBCol::StateShardUIdMapping, &parent_shard_uid.to_bytes())
+          .expect("set_shard_uid_mapping() failed")
+          .unwrap_or(parent_shard_uid);
     self.store_update.set(
         DBCol::StateShardUIdMapping,
         child_shard_uid.to_bytes().as_ref(),
-        &borsh::to_vec(&parent_shard_uid).expect("Borsh serialize cannot fail"),
+        &borsh::to_vec(&mapped_parent_shard_uid).expect("Borsh serialize cannot fail"),
     )
 }
 ```