diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 2ff132a1..907e8bbc 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=3.4.10@sha256:deffb4e6de73422dfe0b93384f6a82e530040048e2df4256aa0f6b22a4cffdff
+ARG RUBY_VERSION=4.0.6@sha256:b7214a536a55d4f126b4695eb0b8bae33f839e5fe399f77521484712b1401b8c
 FROM ghcr.io/rails/devcontainer/images/ruby:$RUBY_VERSION