diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b8a588b..4434e96 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,14 +23,14 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest]
-        ruby: [jruby-9.3.4.0, '2.7', '3.2']
+        ruby: [jruby-9.4, '2.7', '3.3']
         include:
         - os: ubuntu-latest
           ruby: jruby-9.2
         #- os: ubuntu-latest
         #  ruby: truffleruby
         - os: macos-latest
-          ruby: '3.2'
+          ruby: '3.3'
     runs-on: ${{ matrix.os }}
     env:
       # work around `Permission denied - NUL' error when installing/using the bundler gem on JRuby for Windows
diff --git a/asciidoctor-bibtex.gemspec b/asciidoctor-bibtex.gemspec
index fcef30e..b8f2524 100644
--- a/asciidoctor-bibtex.gemspec
+++ b/asciidoctor-bibtex.gemspec
@@ -16,7 +16,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = '>= 2.4.0'
   s.files = Dir['lib/**/*'] + ['LICENSE.txt', 'README.adoc']
   s.add_runtime_dependency 'asciidoctor', '~> 2.0'
-  s.add_runtime_dependency 'bibtex-ruby', '~> 5.1'
+  s.add_runtime_dependency 'bibtex-ruby', '~> 6.1'
   s.add_runtime_dependency 'citeproc-ruby', '~> 1'
   s.add_runtime_dependency 'csl-styles', '~> 1'
   s.add_runtime_dependency 'latex-decode', '~> 0.2'