diff --git a/Dockerfile b/Dockerfile
index 7723fd1..74000b6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:2.6.3-alpine
+FROM ruby:3.1.2-alpine
 LABEL MAINTAINER="ahiru3net"
 
 ARG WORK_DIR="/home/mikutter"