diff --git a/addons/purchase_mrp/models/mrp_production.py b/addons/purchase_mrp/models/mrp_production.py
index ed9dd1878f3..29cbfac9295 100644
--- a/addons/purchase_mrp/models/mrp_production.py
+++ b/addons/purchase_mrp/models/mrp_production.py
@@ -47,7 +47,7 @@ class MrpProduction(models.Model):
     def _prepare_merge_orig_links(self):
         origs = super()._prepare_merge_orig_links()
         for move in self.move_raw_ids:
-            if not move.move_orig_ids:
+            if not move.move_orig_ids or not move.created_purchase_line_ids:
                 continue
             origs[move.bom_line_id.id].setdefault('created_purchase_line_ids', set()).update(move.created_purchase_line_ids.ids)
         for vals in origs.values():