diff --git a/docker-images/mcservers/production/one-day-to-reset/Dockerfile b/docker-images/mcservers/production/one-day-to-reset/Dockerfile
index a24392036..de156f2ca 100644
--- a/docker-images/mcservers/production/one-day-to-reset/Dockerfile
+++ b/docker-images/mcservers/production/one-day-to-reset/Dockerfile
@@ -1,6 +1,6 @@
 FROM ghcr.io/giganticminecraft/seichi_minecraft_server_base:1.0.0-java17-jdk@sha256:911ada718fdab94b19ca83eba4a6e7c77d2354301a2352ddbb9610091a189c07
 
-ENV VERSION="1.20.1"
+ENV VERSION="1.21.1"
 ENV DIFFICULTY="normal"
 
 # プラグインリスト