diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 57d1dfd..e255f47 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,3 +31,21 @@ jobs:
           bundler-cache: true
       - name: Run Unit Tests
         run: bundle exec rake test
+
+  style_check:
+    name: "Style Check (Ruby ${{ matrix.ruby_version }})"
+    runs-on: "ubuntu-latest"
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby_version:
+          - "3.3"
+    steps:
+      - uses: actions/checkout@v4
+      - name: "Set up Ruby ${{ matrix.ruby_version }}"
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby_version }}
+          bundler-cache: true
+      - name: Run RuboCop
+        run:  bash script/fmt
diff --git a/.rubocop.yml b/.rubocop.yml
index 245b600..bcebed9 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,28 +1,27 @@
-require: rubocop-jekyll
+require:
+  - rubocop-jekyll
+  - rubocop-minitest
 
 inherit_gem:
   rubocop-jekyll: .rubocop.yml
 
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.7
+  SuggestExtensions: false
   Exclude:
     - vendor/**/*
 
-Lint/ShadowingOuterLocalVariable:
+Layout/LineLength:
   Exclude:
     - lib/jekyll-archives.rb
-
-# Remove once Jekyll core has dropped explicit support for Ruby 2.2
-Lint/SafeNavigationConsistency:
-  Exclude:
     - lib/jekyll-archives/archive.rb
+    - test/**/*.rb
 
 Metrics/BlockLength:
   Exclude:
     - test/**/*.rb
 
-Metrics/LineLength:
-  Exclude:
-    - lib/jekyll-archives.rb
-    - lib/jekyll-archives/archive.rb
-    - test/**/*.rb
+Minitest/AssertKindOf:
+  Enabled: true
+Minitest/EmptyLineBeforeAssertionMethods:
+  Enabled: true
diff --git a/Gemfile b/Gemfile
index cbec53b..4fad357 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,3 +5,9 @@ gemspec
 
 gem "jekyll", ENV["JEKYLL_VERSION"] if ENV["JEKYLL_VERSION"]
 gem "kramdown-parser-gfm" if ENV["JEKYLL_VERSION"] == "~> 3.9"
+
+gem "minitest"
+gem "rake"
+gem "rubocop-jekyll", "~> 0.14.0"
+gem "rubocop-minitest"
+gem "shoulda-context"
diff --git a/jekyll-archives.gemspec b/jekyll-archives.gemspec
index 6afb827..5afeaf7 100644
--- a/jekyll-archives.gemspec
+++ b/jekyll-archives.gemspec
@@ -15,14 +15,7 @@ Gem::Specification.new do |s|
   all_files     = `git ls-files -z`.split("\x0")
   s.files       = all_files.grep(%r!^(lib)/!)
 
-  s.required_ruby_version = ">= 2.3.0"
+  s.required_ruby_version = ">= 2.7.0"
 
   s.add_dependency "jekyll", ">= 3.6", "< 5.0"
-
-  s.add_development_dependency "bundler"
-  s.add_development_dependency "minitest"
-  s.add_development_dependency "rake"
-  s.add_development_dependency "rdoc"
-  s.add_development_dependency "rubocop-jekyll", "~> 0.9"
-  s.add_development_dependency "shoulda"
 end
diff --git a/lib/jekyll-archives.rb b/lib/jekyll-archives.rb
index d0a2a26..a84bd11 100644
--- a/lib/jekyll-archives.rb
+++ b/lib/jekyll-archives.rb
@@ -133,7 +133,7 @@ def append_enabled_date_type(meta, type, posts)
       def date_attr_hash(posts, id)
         hash = Hash.new { |hsh, key| hsh[key] = [] }
         posts.each { |post| hash[post.date.strftime(id)] << post }
-        hash.each_value { |posts| posts.sort!.reverse! }
+        hash.each_value { |posts_in_hsh| posts_in_hsh.sort!.reverse! }
         hash
       end
     end
diff --git a/lib/jekyll-archives/archive.rb b/lib/jekyll-archives/archive.rb
index ac4a45a..da75b47 100644
--- a/lib/jekyll-archives/archive.rb
+++ b/lib/jekyll-archives/archive.rb
@@ -77,11 +77,11 @@ def url
           :permalink    => nil
         ).to_s
       rescue ArgumentError
-        raise ArgumentError, "Template \"#{template}\" provided is invalid."
+        raise ArgumentError, "Template #{template.inspect} provided is invalid."
       end
 
       def permalink
-        data&.is_a?(Hash) && data["permalink"]
+        data.is_a?(Hash) && data["permalink"]
       end
 
       # Produce a title object suitable for Liquid based on type of archive.
@@ -89,7 +89,7 @@ def permalink
       # Returns a String (for tag and category archives) and nil for
       # date-based archives.
       def title
-        @title if @title.is_a? String
+        @title if @title.is_a?(String)
       end
 
       # Produce a date object if a date-based archive
diff --git a/script/fmt b/script/fmt
index 872d0ee..ec087cd 100755
--- a/script/fmt
+++ b/script/fmt
@@ -1,8 +1,8 @@
 #!/bin/bash
 set -e
 
-echo "Rubocop $(bundle exec rubocop --version)"
-bundle exec rubocop -S -D -E $@
+echo "RuboCop $(bundle exec rubocop --version)"
+bundle exec rubocop -E --disable-pending-cops $@
 success=$?
 if ((success != 0)); then
    echo -e "\nTry running \`script/fmt -a\` to automatically fix errors"
diff --git a/test/helper.rb b/test/helper.rb
index c4eda43..4ec0b8b 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -5,16 +5,12 @@
 
 require "rubygems"
 require "minitest/autorun"
-require "shoulda"
+require "shoulda/context"
 
-$LOAD_PATH.unshift(File.join(__dir__, "..", "lib"))
-$LOAD_PATH.unshift(__dir__)
+require_relative "../lib/jekyll-archives"
 
-require "jekyll-archives"
-
-TEST_DIR     = __dir__
-SOURCE_DIR   = File.expand_path("source", TEST_DIR)
-DEST_DIR     = File.expand_path("destination", TEST_DIR)
+SOURCE_DIR = File.expand_path("source", __dir__)
+DEST_DIR   = File.expand_path("destination", __dir__)
 
 module Minitest
   class Test
diff --git a/test/test_jekyll_archive.rb b/test/test_jekyll_archive.rb
index 9232389..e38b51d 100644
--- a/test/test_jekyll_archive.rb
+++ b/test/test_jekyll_archive.rb
@@ -27,6 +27,7 @@ class TestJekyllArchive < Minitest::Test
         "url"       => "/tag/test-tag/",
         "permalink" => nil,
       }
+
       assert_equal expected, archive.to_liquid.to_h
 
       archive = @archives.find { |a| a.type == "category" }
@@ -42,6 +43,7 @@ class TestJekyllArchive < Minitest::Test
         "url"       => "/category/plugins/",
         "permalink" => nil,
       }
+
       assert_equal expected, archive.to_liquid.to_h
 
       archive = @archives.find { |a| a.type == "year" }
@@ -57,6 +59,7 @@ class TestJekyllArchive < Minitest::Test
         "url"       => "/2013/",
         "permalink" => nil,
       }
+
       assert_equal expected, archive.to_liquid.to_h
 
       archive = @archives.find { |a| a.type == "month" }
@@ -72,6 +75,7 @@ class TestJekyllArchive < Minitest::Test
         "url"       => "/2013/08/",
         "permalink" => nil,
       }
+
       assert_equal expected, archive.to_liquid.to_h
 
       archive = @archives.find { |a| a.type == "day" }
@@ -87,6 +91,7 @@ class TestJekyllArchive < Minitest::Test
         "url"       => "/2013/08/16/",
         "permalink" => nil,
       }
+
       assert_equal expected, archive.to_liquid.to_h
     end
   end
diff --git a/test/test_jekyll_archives.rb b/test/test_jekyll_archives.rb
index 8ccbd84..2ac1ea1 100644
--- a/test/test_jekyll_archives.rb
+++ b/test/test_jekyll_archives.rb
@@ -14,24 +14,28 @@ class TestJekyllArchives < Minitest::Test
 
     should "generate archive pages by year" do
       @archives.generate(@site)
+
       assert archive_exists? @site, "2014/index.html"
       assert archive_exists? @site, "2013/index.html"
     end
 
     should "generate archive pages by month" do
       @archives.generate(@site)
+
       assert archive_exists? @site, "2014/08/index.html"
       assert archive_exists? @site, "2014/03/index.html"
     end
 
     should "generate archive pages by day" do
       @archives.generate(@site)
+
       assert archive_exists? @site, "2014/08/17/index.html"
       assert archive_exists? @site, "2013/08/16/index.html"
     end
 
     should "generate archive pages by tag" do
       @archives.generate(@site)
+
       assert archive_exists? @site, "tag/test-tag/index.html"
       assert archive_exists? @site, "tag/tagged/index.html"
       assert archive_exists? @site, "tag/new/index.html"
@@ -39,11 +43,13 @@ class TestJekyllArchives < Minitest::Test
 
     should "generate archive pages by category" do
       @archives.generate(@site)
+
       assert archive_exists? @site, "category/plugins/index.html"
     end
 
     should "generate archive pages with a layout" do
       @site.process
+
       assert_equal "Test", read_file("tag/test-tag/index.html")
     end
   end
@@ -62,6 +68,7 @@ class TestJekyllArchives < Minitest::Test
 
     should "generate slugs using the mode specified" do
       @archives.generate(@site)
+
       assert archive_exists? @site, "category/💎/index.html"
     end
   end
@@ -77,6 +84,7 @@ class TestJekyllArchives < Minitest::Test
 
     should "use custom layout" do
       @site.process
+
       assert_equal "Test too", read_file("tag/test-tag/index.html")
     end
   end
@@ -164,10 +172,10 @@ class TestJekyllArchives < Minitest::Test
     end
 
     should "not generate the disabled archives" do
-      assert !archive_exists?(@site, "2014/index.html")
-      assert !archive_exists?(@site, "2014/08/index.html")
-      assert !archive_exists?(@site, "2013/08/16/index.html")
-      assert !archive_exists?(@site, "category/plugins/index.html")
+      refute archive_exists?(@site, "2014/index.html")
+      refute archive_exists?(@site, "2014/08/index.html")
+      refute archive_exists?(@site, "2013/08/16/index.html")
+      refute archive_exists?(@site, "category/plugins/index.html")
     end
   end
 
@@ -186,25 +194,25 @@ class TestJekyllArchives < Minitest::Test
     end
 
     should "populate the title field in case of category or tag" do
-      assert @tag_archive.title.is_a? String
-      assert @category_archive.title.is_a? String
+      assert_kind_of String, @tag_archive.title
+      assert_kind_of String, @category_archive.title
     end
 
     should "use nil for the title field in case of dates" do
-      assert @year_archive.title.nil?
-      assert @month_archive.title.nil?
-      assert @day_archive.title.nil?
+      assert_nil @year_archive.title
+      assert_nil @month_archive.title
+      assert_nil @day_archive.title
     end
 
     should "use nil for the date field in case of category or tag" do
-      assert @tag_archive.date.nil?
-      assert @category_archive.date.nil?
+      assert_nil @tag_archive.date
+      assert_nil @category_archive.date
     end
 
     should "populate the date field with a Date in case of dates" do
-      assert @year_archive.date.is_a? Date
-      assert @month_archive.date.is_a? Date
-      assert @day_archive.date.is_a? Date
+      assert_kind_of Date, @year_archive.date
+      assert_kind_of Date, @month_archive.date
+      assert_kind_of Date, @day_archive.date
     end
   end
 
@@ -215,6 +223,7 @@ class TestJekyllArchives < Minitest::Test
         site.read
         site.generate
       end
+
       assert_includes output, "Archives: Expected a hash but got [\"apples\", \"oranges\"]"
       assert_includes output, "Archives will not be generated for this site."
 
@@ -223,6 +232,7 @@ class TestJekyllArchives < Minitest::Test
         site.read
         site.generate
       end
+
       assert_includes output, "Archives: Expected a hash but got nil"
       assert_includes output, "Archives will not be generated for this site."
     end
@@ -232,6 +242,7 @@ class TestJekyllArchives < Minitest::Test
         site = fixture_site("jekyll-archives" => nil)
         site.read
         site.generate
+
         assert_nil(site.pages.find { |p| p.is_a?(Jekyll::Archives::Archive) })
       end
     end
@@ -242,6 +253,7 @@ class TestJekyllArchives < Minitest::Test
         @site.read
         @site.generate
       end
+
       refute_includes output, "Archives: Expected a hash but got nil"
       assert_nil(@site.pages.find { |p| p.is_a?(Jekyll::Archives::Archive) })
     end