diff --git a/.gitignore b/.gitignore
index 7bc135c..ac36ab6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,3 +70,5 @@ yarn-debug.log*
 !/storage/.keep
 
 /config/master.key
+
+.DS_Store
diff --git a/Dockerfile b/Dockerfile
index b07f435..9b98c38 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,7 @@
-# syntax = docker/dockerfile:1
+# syntax=docker/dockerfile:1
+# check=error=true
 
-# This Dockerfile is designed for production, not development. Use with Kamal or build'n'run by hand:
+# This Dockerfile is designed for production, not development.
 # docker build -t my-app .
 # docker run -d -p 80:80 -p 443:443 --name my-app -e RAILS_MASTER_KEY=<value from config/master.key> my-app
 
@@ -46,8 +47,6 @@ RUN bundle exec bootsnap precompile app/ lib/
 RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
 
 
-
-
 # Final stage for app image
 FROM base
 
diff --git a/README.md b/README.md
index f9aff13..a129830 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ This app demonstrates Rails 7 with PostgreSQL, import maps, turbo, stimulus and
 ## Features
 
 * Rails 7
-* Ruby 3
+* Ruby 3.3
 * Dockerfile and Docker Compose configuration
 * PostgreSQL database
 * Redis