diff --git a/.devcontainer/base.Dockerfile b/.devcontainer/base.Dockerfile
index 9e3296a..8265aee 100644
--- a/.devcontainer/base.Dockerfile
+++ b/.devcontainer/base.Dockerfile
@@ -1,5 +1,5 @@
 # [Choice] Debian OS version (use 2.7-bullseye on local arm64/Apple Silicon): 2.7-bullseye, 2.7-buster
-ARG VARIANT=2.7-bullseye
+ARG VARIANT=3.4-bullseye
 FROM mcr.microsoft.com/vscode/devcontainers/ruby:${VARIANT}
 COPY library-scripts/meta.env /usr/local/etc/vscode-dev-containers