diff --git a/3.1/18/alpine/Dockerfile b/3.1/18/alpine/Dockerfile
index 44cfb56..0821437 100644
--- a/3.1/18/alpine/Dockerfile
+++ b/3.1/18/alpine/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:3.1-alpine
+FROM ruby:3.3.5-alpine
 LABEL maintainer "Tim Brust <github@timbrust.de>"
 
 ARG REFRESHED_AT