diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 340edb3f..103d7a4a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,13 +9,11 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-          - '2.7'
           - '3.0'
           - '3.1'
           - '3.2'
           - '3.3'
-          # When 3.4 is released, replace `ruby-head` with `3.4`, `3.4.0-rc1` can't be used on `windows-latest`
-          - 'ruby-head'
+          - '3.4'
         os:
           - 'ubuntu-latest'
           - 'windows-latest'
@@ -30,4 +28,4 @@ jobs:
       run: bundle exec rake test
     - name: RuboCop
       run: bundle exec rake lint
-      if: matrix.ruby != '3.1' && matrix.ruby != '3.2' && matrix.ruby != '3.3' && matrix.ruby != 'ruby-head'
+      if:  matrix.ruby == '3.0'
diff --git a/pg_query.gemspec b/pg_query.gemspec
index 4330650a..1ae7b5ad 100644
--- a/pg_query.gemspec
+++ b/pg_query.gemspec
@@ -12,6 +12,8 @@ Gem::Specification.new do |s|
   s.license     = 'BSD-3-Clause'
   s.homepage    = 'https://github.com/pganalyze/pg_query'
 
+  s.required_ruby_version = '>= 3.0'
+
   s.extensions = %w[ext/pg_query/extconf.rb]
 
   s.files = Dir['CHANGELOG.md', 'LICENSE', 'README.md', 'Rakefile', 'lib/**/*.rb',