diff --git a/module/advancement/advancement-manager.mjs b/module/advancement/advancement-manager.mjs
index 282f41c826..2c5c420efa 100644
--- a/module/advancement/advancement-manager.mjs
+++ b/module/advancement/advancement-manager.mjs
@@ -33,7 +33,7 @@ export default class AdvancementManager extends Application {
      * A clone of the original actor to which the changes can be applied during the advancement process.
      * @type {Actor5e}
      */
-    this.clone = actor.clone();
+    this.clone = actor.clone({}, {keepId: true});
 
     /**
      * Individual steps that will be applied in order.
diff --git a/module/advancement/types/subclass.mjs b/module/advancement/types/subclass.mjs
index 6cf93afe1b..777e63b925 100644
--- a/module/advancement/types/subclass.mjs
+++ b/module/advancement/types/subclass.mjs
@@ -71,7 +71,7 @@ export class SubclassAdvancement extends Advancement {
         _id: foundry.utils.randomID(),
         "system.classIdentifier": this.item.identifier,
         "flags.dnd5e.sourceId": data.uuid,
-        "flags.dnd5e.advancementOrigin": `${this.item.id}.${this.id}`
+        "flags.dnd5e.advancementOrigin": this.uuid
       }, {keepId: true}).toObject();
     }
     this.actor.updateSource({ items: [itemData] });