diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 7e1d37ba..4b308fdc 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -1,5 +1,5 @@
 # [Choice] Ruby version (use -bullseye variants on local arm64/Apple Silicon): 3, 3.1, 3.0, 2, 2.7, 2.6, 3-bullseye, 3.1-bullseye, 3.0-bullseye, 2-bullseye, 2.7-bullseye, 2.6-bullseye, 3-buster, 3.1-buster, 3.0-buster, 2-buster, 2.7-buster, 2.6-buster
-ARG VARIANT="3.3.4"
+ARG VARIANT="3.4.5"
 FROM ghcr.io/rails/devcontainer/images/ruby:${VARIANT}
 
 # Default value to allow debug server to serve content over GitHub Codespace's port forwarding service
@@ -7,8 +7,8 @@ FROM ghcr.io/rails/devcontainer/images/ruby:${VARIANT}
 ENV RAILS_DEVELOPMENT_HOSTS=".githubpreview.dev"
 
 # [Optional] Uncomment this section to install additional OS packages.
-RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
-    && apt-get -y install --no-install-recommends cmake pkg-config
+RUN sudo apt-get update && export DEBIAN_FRONTEND=noninteractive \
+    && sudo apt-get -y install --no-install-recommends cmake pkg-config
 
 # [Optional] Uncomment this line to install additional gems.
 # RUN gem install <your-gem-names-here>
@@ -17,4 +17,4 @@ RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
 # RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g <your-package-here>" 2>&1
 
 # Donwload rails repository locally to do calculations on the repository
-RUN git clone --mirror https://github.com/rails/rails.git
+RUN sudo git clone --mirror https://github.com/rails/rails.git
diff --git a/.devcontainer/docker-compose.yml b/.devcontainer/docker-compose.yml
index 7b20fa86..d7af63dd 100644
--- a/.devcontainer/docker-compose.yml
+++ b/.devcontainer/docker-compose.yml
@@ -9,7 +9,7 @@ services:
         # Update 'VARIANT' to pick a version of Ruby: 3, 3.1, 3.0, 2, 2.7, 2.6
         # Append -bullseye or -buster to pin to an OS version.
         # Use -bullseye variants on local arm64/Apple Silicon.
-        VARIANT: "3.3.4"
+        VARIANT: "3.4.5"
 
     volumes:
       - ..:/workspaces:cached
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8ca7a9a4..de2c73b8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -38,7 +38,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.3.4
+        ruby-version: 3.4.5
         bundler-cache: true
 
     - name: Run tests
diff --git a/.ruby-version b/.ruby-version
index a0891f56..4f5e6973 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.3.4
+3.4.5
diff --git a/Dockerfile b/Dockerfile
index ad45073e..5311d9bd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@
 #   * .ruby-version (used by CircleCI).
 #   * Install the version by hand in the server (uses RVM).
 #
-FROM ruby:3.3.4-alpine3.20
+FROM ruby:3.4.5-alpine3.22
 
 # LANG as recommended in the Encoding section of https://hub.docker.com/_/ruby/.
 ENV LANG C.UTF-8
diff --git a/Gemfile b/Gemfile
index 9d2b1fb9..525b1d91 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-ruby '3.3.4'
+ruby '3.4.5'
 
 source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
diff --git a/Gemfile.lock b/Gemfile.lock
index 321031f2..34e52f37 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -296,7 +296,7 @@ DEPENDENCIES
   web-console (>= 3.3.0)
 
 RUBY VERSION
-   ruby 3.3.4p94
+   ruby 3.4.5p51
 
 BUNDLED WITH
    2.5.17
diff --git a/app/models/commit.rb b/app/models/commit.rb
index f9d471bc..f11380f5 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 class Commit < ApplicationRecord
   has_many :contributions, dependent: :destroy
   has_many :contributors, through: :contributions
@@ -196,7 +198,7 @@ def cache_diff(repo)
   # git show, and is an expensive operation. So, we do this only for those
   # commits where this is needed, and cache the result in the database.
   def extract_changelog
-    changelog = ''
+    changelog = +''
     in_changelog = false
     diff.each_line do |line|
       if line =~ /^diff --git/
diff --git a/config/deploy/production.rb b/config/deploy/production.rb
index 32779bd4..58852eeb 100644
--- a/config/deploy/production.rb
+++ b/config/deploy/production.rb
@@ -8,7 +8,7 @@
 set :puma_workers, 1
 set :puma_phased_restart, true
 
-set :rvm_ruby_version, '3.3.4'
+set :rvm_ruby_version, '3.4.5'
 set :rvm_custom_path, '/home/rails/.rvm'
 
 namespace :deploy do
diff --git a/test/models/commit_test.rb b/test/models/commit_test.rb
index 606b599a..1ee98e21 100644
--- a/test/models/commit_test.rb
+++ b/test/models/commit_test.rb
@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 require 'ostruct'
 
@@ -22,7 +24,7 @@ def test_import
     tcomm = Time.current
     tauth = 1.day.ago
 
-    message = <<-MSG.strip_heredoc
+    message = +<<-MSG.strip_heredoc
       \u{1f4a3}
 
       We are relying on hash inequality in tests
@@ -32,8 +34,8 @@ def test_import
       sha1 = "b5ed79468289c15a685a82694dcf1adf773c91d#{i}"
       rugged_commit = OpenStruct.new
       rugged_commit.oid       = sha1
-      rugged_commit.author    = {name: 'Juanjo', email: 'juanjo@example.com', time: tauth}
-      rugged_commit.committer = {name: 'David', email: 'david@example.com', time: tcomm}
+      rugged_commit.author    = {name: +'Juanjo', email: +'juanjo@example.com', time: tauth}
+      rugged_commit.committer = {name: +'David', email: +'david@example.com', time: tcomm}
       rugged_commit.message   = message
       rugged_commit.parents   = parents