diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 6476170..7f9454b 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -7,11 +7,6 @@
   "name": "Jekyll",
   "image": "mcr.microsoft.com/devcontainers/jekyll",
   "features": {
-    // Install rbenv (no Ruby yet); postCreateCommand installs the version from .ruby-version
-    "ghcr.io/devcontainers/features/ruby:2": {
-      "version": "none",
-      "versionManager": "rbenv"
-    },
     // Install nvm (no Node yet); postCreateCommand installs the version from .nvmrc
     "ghcr.io/devcontainers/features/node:2": {
       "version": "none",
@@ -20,7 +15,8 @@
     }
   },
   // Ruby and Node versions come from .ruby-version and .nvmrc (single source of truth, shared with CI)
-  "postCreateCommand": "/bin/bash -c 'set -e; rbenv install --skip-existing; rbenv rehash; source \"$NVM_DIR/nvm.sh\"; nvm install; nvm use; npm install -g corepack; corepack enable; corepack prepare yarn@4.18.0 --activate; yarn install --immutable; bundle install'",
+  // We depend on the Jekyll image having RVM + ruby-build installed
+  "postCreateCommand": "bash -lc 'set -e; source /usr/local/rvm/scripts/rvm; rvm install \"$(tr -d \"[:space:]\" < .ruby-version)\"; rvm use \"$(tr -d \"[:space:]\" < .ruby-version)\" --default; . \"$NVM_DIR/nvm.sh\"; nvm install; nvm use; npm install -g corepack; corepack enable; corepack install; yarn install --immutable; bundle install'",
   "customizations": {
     "vscode": {
       "extensions": ["html-validate.vscode-html-validate"]