diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc96894..d2f481f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,7 +20,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.0', 3.1, 3.2, ruby-head, jruby]
+        ruby: ['3.0', 3.1, 3.2, 3.3, ruby-head, jruby]
         gemfile:
           - Gemfile
           - Gemfile-pure
@@ -37,6 +37,6 @@ jobs:
         run: ruby --version; bundle exec rspec spec || $ALLOW_FAILURES
       - name: Coveralls GitHub Action
         uses: coverallsapp/github-action@v2
-        if: ${{ matrix.ruby == '3.2' && matrix.gemfile == 'Gemfile' }}
+        if: ${{ matrix.ruby == '3.3' && matrix.gemfile == 'Gemfile' }}
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/README.md b/README.md
index 229acfe..fd8bf73 100755
--- a/README.md
+++ b/README.md
@@ -41,6 +41,10 @@ Write a graph to a file:
        writer << graph
     end
 
+## Change Log
+
+See [Release Notes on GitHub](https://github.com/ruby-rdf/rdf-rdfxml/releases)
+
 ## Dependencies
 * [RDF.rb](https://rubygems.org/gems/rdf) (~> 3.3)
 * [Builder](https://rubygems.org/gems/builder) (~>- 3.2)
diff --git a/rdf-rdfxml.gemspec b/rdf-rdfxml.gemspec
index 238e310..7a720d7 100755
--- a/rdf-rdfxml.gemspec
+++ b/rdf-rdfxml.gemspec
@@ -33,6 +33,7 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency     'htmlentities',    '~> 4.3'
   gem.add_runtime_dependency     'builder',         '~> 3.2', '>= 3.2.4'
 
+  gem.add_development_dependency 'getoptlong',      '~> 0.2'
   gem.add_development_dependency 'json-ld',         '>= 3.3'
   gem.add_development_dependency 'rspec',           '~> 3.12'
   gem.add_development_dependency 'rspec-its',       '~> 1.3'