diff --git a/samples/sample-book/src/config.yml b/samples/sample-book/src/config.yml
index 8e7631c69..e797da48e 100644
--- a/samples/sample-book/src/config.yml
+++ b/samples/sample-book/src/config.yml
@@ -3,7 +3,6 @@ review_version: 5.0
 bookname: book
 language: ja
 booktitle: Re:VIEWサンプル書籍
-urnid: urn:uuid:http://reviewml.com/books/review-sample-book/
 # isbn: null
 aut: Re:VIEW Writers
 pbl: Re:VIEW Publishers