diff --git a/_config.yml b/_config.yml
index bdee5823a..15e0772e1 100644
--- a/_config.yml
+++ b/_config.yml
@@ -1,8 +1,8 @@
 title: PGroonga
 markdown: kramdown
 highlighter: rouge
-pgroonga_version: 3.1.3
-pgroonga_release_date: 2023-08-17
+pgroonga_version: 3.1.5
+pgroonga_release_date: 2023-09-29
 postgresql_doc_base_url:
   en: https://www.postgresql.org/docs/16
   ja: https://www.postgresql.jp/document/15/html