diff --git a/lib/Element.ts b/lib/Element.ts
index 9c625d3..275b8e5 100644
--- a/lib/Element.ts
+++ b/lib/Element.ts
@@ -16,7 +16,7 @@ export class Element {
     const new_name = val.replace (/[^a-z0-9]/giu, '')
       .replace (/^[0-9]+/iu, '');
     if (new_name === '')
-      throw new Error ('invalid name specified');
+      throw new Error (`invalid node name ${val}`);
     this._name = new_name;
   }