diff --git a/lib/JsonLdDocumentLoader.js b/lib/JsonLdDocumentLoader.js
index fb212ad..6bc4a67 100644
--- a/lib/JsonLdDocumentLoader.js
+++ b/lib/JsonLdDocumentLoader.js
@@ -16,7 +16,7 @@ export class JsonLdDocumentLoader {
     if(!_isObject(document)) {
       throw new TypeError('The second parameter (document) must be an object.');
     }
-    this.documents.set(url, klona(document));
+    this.documents.set(url, structuredClone(document));
   }
 
   /**