diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dc8083e..dbefeae 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,4 @@
-name: 'Continuous Integration'
+name: 'CI'
 on:
   push:
     branches-ignore:
@@ -18,23 +18,20 @@ on:
       - '**'
 
 jobs:
-  ci:
-    runs-on: ${{ matrix.os }}
+  build:
+    runs-on: ubuntu-latest
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest]
-
+        ruby: [2.5, 2.6, 2.7, 3]
     steps:
       - name: Checkout
         uses: actions/checkout@v2
         with:
           fetch-depth: 0  # for posts's lastmod
-
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.7
+          ruby-version: ${{ matrix.ruby }}
           bundler-cache: true
-
       - name: Test Site
         run: bash tools/deploy.sh --dry-run
diff --git a/jekyll-theme-chirpy.gemspec b/jekyll-theme-chirpy.gemspec
index 9bcf35a..47ae500 100644
--- a/jekyll-theme-chirpy.gemspec
+++ b/jekyll-theme-chirpy.gemspec
@@ -16,14 +16,14 @@ Gem::Specification.new do |spec|
 
   spec.metadata = {
     "bug_tracker_uri"   => "https://github.com/cotes2020/jekyll-theme-chirpy/issues",
-    "documentation_uri" => "https://github.com/cotes2020/jekyll-theme-chirpy/blob/master/README.md",
+    "documentation_uri" => "https://github.com/cotes2020/jekyll-theme-chirpy/#readme",
     "homepage_uri"      => "https://cotes2020.github.io/chirpy-demo",
     "source_code_uri"   => "https://github.com/cotes2020/jekyll-theme-chirpy",
     "wiki_uri"          => "https://github.com/cotes2020/jekyll-theme-chirpy/wiki",
     "plugin_type"       => "theme"
   }
 
-  spec.required_ruby_version = ">= 2.4"
+  spec.required_ruby_version = ">= 2.5"
 
   spec.add_runtime_dependency "jekyll", "~> 4.1"
   spec.add_runtime_dependency "jekyll-paginate", "~> 1.1"