diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9f9a27b..57e7684 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,14 +20,18 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-          - "3.0"
           - "3.1"
           - "3.2"
-          - "ruby-head"
+          # - "ruby-head"
     steps:
-      - uses: actions/checkout@v4
-      - uses: ruby/setup-ruby@v1
+      - name: Install system dependencies
+        run: sudo apt-get install imagemagick libmagickwand-dev
+      - name: Check out code
+        uses: actions/checkout@v4
+      - name: Install Ruby dependencies
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true
-      - run: bundle exec rake test
+      - name: Run tests
+        run: bundle exec rake test
diff --git a/Dockerfile b/Dockerfile
index 135b1ac..7598a32 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -26,10 +26,10 @@ RUN apk update && apk upgrade
 RUN apk add build-base bash ruby ruby-etc ruby-dev
 
 # Install builtin fonts
-RUN gem install invoice_printer_fonts --version 2.3.0 --no-document
+RUN gem install invoice_printer_fonts --version 2.4.0 --no-document
 
 # Install the gem from RubyGems.org
-RUN gem install invoice_printer_server --version 2.3.0 --no-document
+RUN gem install invoice_printer_server --version 2.4.0 --no-document
 
 # Clean APK cache
 RUN rm -rf /var/cache/apk/*
diff --git a/Gemfile.lock b/Gemfile.lock
deleted file mode 100644
index 6f92d75..0000000
--- a/Gemfile.lock
+++ /dev/null
@@ -1,84 +0,0 @@
-PATH
-  remote: .
-  specs:
-    invoice_printer (2.3.0)
-      e2mmap
-      json (~> 2.1)
-      matrix
-      prawn (~> 2.4)
-      prawn-table (~> 0.2.2)
-    invoice_printer_server (2.3.0)
-      invoice_printer (= 2.3.0)
-      json (~> 2.1)
-      puma (>= 3.9.0)
-      roda (~> 3.5)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    Ascii85 (1.1.1)
-    afm (0.2.2)
-    benchmark_driver (0.15.17)
-    benchmark_driver-output-gruff (0.3.1)
-      benchmark_driver (>= 0.12.0)
-      gruff
-    bigdecimal (3.1.8)
-    e2mmap (0.1.0)
-    gruff (0.25.0)
-      bigdecimal (>= 3.0)
-      histogram
-      rmagick (>= 5.5)
-    hashery (2.1.2)
-    histogram (0.2.4.1)
-    json (2.7.2)
-    matrix (0.4.2)
-    minitest (5.25.1)
-    nio4r (2.7.3)
-    observer (0.1.2)
-    pdf-core (0.10.0)
-    pdf-inspector (1.3.0)
-      pdf-reader (>= 1.0, < 3.0.a)
-    pdf-reader (2.12.0)
-      Ascii85 (~> 1.0)
-      afm (~> 0.2.1)
-      hashery (~> 2.0)
-      ruby-rc4
-      ttfunk
-    pkg-config (1.5.6)
-    prawn (2.5.0)
-      matrix (~> 0.4)
-      pdf-core (~> 0.10.0)
-      ttfunk (~> 1.8)
-    prawn-table (0.2.2)
-      prawn (>= 1.3.0, < 3.0.0)
-    puma (6.4.3)
-      nio4r (~> 2.0)
-    rack (3.1.7)
-    rack-test (2.1.0)
-      rack (>= 1.3)
-    rake (13.2.1)
-    rmagick (6.0.1)
-      observer (~> 0.1)
-      pkg-config (~> 1.4)
-    roda (3.85.0)
-      rack
-    ruby-rc4 (0.1.5)
-    ttfunk (1.8.0)
-      bigdecimal (~> 3.1)
-
-PLATFORMS
-  arm64-darwin-22
-  ruby
-
-DEPENDENCIES
-  benchmark_driver (= 0.15.17)
-  benchmark_driver-output-gruff
-  bundler (>= 1.7)
-  invoice_printer_server!
-  minitest
-  pdf-inspector
-  rack-test
-  rake (>= 10.0)
-
-BUNDLED WITH
-   2.5.15
diff --git a/lib/invoice_printer/version.rb b/lib/invoice_printer/version.rb
index ff16003..4877812 100644
--- a/lib/invoice_printer/version.rb
+++ b/lib/invoice_printer/version.rb
@@ -1,3 +1,3 @@
 module InvoicePrinter
-  VERSION = '2.3.0'
+  VERSION = '2.4.0'
 end