diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index a79e3649..6eeb34ad 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -1,3 +1,3 @@
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version
-ARG RUBY_VERSION=3.4.2
+ARG RUBY_VERSION=3.4.9@sha256:43b922bd50b1e34ae37966707c48e67c26c0657c48c113182785a395d113ba17
 FROM ghcr.io/rails/devcontainer/images/ruby:$RUBY_VERSION