diff --git a/.ruby-version b/.ruby-version
index 90cdbdc..1cf76f5 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-ruby-4.0.1
+ruby-4.0.6
diff --git a/.tool-versions b/.tool-versions
index 6e03b21..05913ea 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1 +1 @@
-ruby 4.0.1
+ruby 4.0.6
diff --git a/Dockerfile b/Dockerfile
index d79b5f9..a8a15ac 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@
 # For a containerized dev environment, see Dev Containers: https://guides.rubyonrails.org/getting_started_with_devcontainer.html
 
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version
-ARG RUBY_VERSION=3.3.4
+ARG RUBY_VERSION=4.0.6
 FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base
 
 # Rails app lives here
diff --git a/Gemfile b/Gemfile
index 86962ff..a065f5f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,5 @@
 source "https://rubygems.org"
-ruby "4.0.1"
+ruby "4.0.6"
 
 gem "bcrypt", "~> 3.1"
 gem "bootsnap", require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 4fe9fb0..5c987c6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -581,7 +581,7 @@ DEPENDENCIES
   web-console
 
 RUBY VERSION
-  ruby 4.0.1
+  ruby 4.0.6
 
 BUNDLED WITH
   4.0.0
diff --git a/README.md b/README.md
index 3853962..dd86341 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Student Visit Application
 
-![Ruby Version](https://img.shields.io/badge/ruby-3.3.4-red.svg)
+![Ruby Version](https://img.shields.io/badge/ruby-4.0.6-red.svg)
 ![Rails Version](https://img.shields.io/badge/rails-8.1.1-red.svg)
 ![PostgreSQL](https://img.shields.io/badge/postgresql-supported-blue.svg)
 
@@ -19,7 +19,7 @@ A comprehensive web application for managing student visits, appointments, and q
 
 ## Technology Stack
 
-- **Ruby**: 3.3.4
+- **Ruby**: 4.0.6
 - **Rails**: 8.1.1
 - **Database**: PostgreSQL (staging/production), SQLite3 (development/test)
 - **Frontend**: Tailwind CSS, Stimulus.js, Turbo
@@ -33,7 +33,7 @@ A comprehensive web application for managing student visits, appointments, and q
 
 ### System Dependencies
 
-- Ruby 3.3.4
+- Ruby 4.0.6
 - PostgreSQL (for staging/production environments)
 - Node.js and npm/yarn (for asset compilation)
 - ImageMagick (for image processing)
@@ -71,9 +71,9 @@ echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
 echo 'eval "$(rbenv init -)"' >> ~/.bashrc
 source ~/.bashrc
 
-# Install Ruby 3.3.4
-rbenv install 3.3.4
-rbenv global 3.3.4
+# Install Ruby 4.0.6
+rbenv install 4.0.6
+rbenv global 4.0.6
 
 # Verify installation
 ruby -v
@@ -295,7 +295,7 @@ sudo certbot --nginx -d your-domain.com
 
 ### Prerequisites
 
-- Ruby 3.3.4
+- Ruby 4.0.6
 - SQLite3 (for development)
 - Node.js 20+
 
diff --git a/config/deploy.yml b/config/deploy.yml
index 7842748..bc4df65 100644
--- a/config/deploy.yml
+++ b/config/deploy.yml
@@ -82,7 +82,7 @@ builder:
   #
   # # Pass arguments and secrets to the Docker build process
   # args:
-  #   RUBY_VERSION: ruby-3.3.4
+  #   RUBY_VERSION: ruby-4.0.6
   # secrets:
   #   - GITHUB_TOKEN
   #   - RAILS_MASTER_KEY