diff --git a/.github/workflows/codecov.yml b/.github/workflows/codecov.yml
index 7ba254f..49d705e 100644
--- a/.github/workflows/codecov.yml
+++ b/.github/workflows/codecov.yml
@@ -8,13 +8,13 @@ jobs:
   codecov:
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-ruby@v1
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.7
+          ruby-version: '2.7'
       - run: bundle update
       - run: bundle exec rake
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v3
         with:
           file: coverage/.resultset.json
           fail_ci_if_error: true
diff --git a/.github/workflows/rake.yml b/.github/workflows/rake.yml
index 16524dc..0923e96 100644
--- a/.github/workflows/rake.yml
+++ b/.github/workflows/rake.yml
@@ -16,8 +16,8 @@ jobs:
         ruby: ['2.7', '3.0']
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-ruby@v1
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
       - run: bundle update
diff --git a/.simplecov b/.simplecov
index 8166f4e..282adf3 100644
--- a/.simplecov
+++ b/.simplecov
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/Gemfile b/Gemfile
index a05a668..35b4ca5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/LICENSE.txt b/LICENSE.txt
index b5d05f4..88ad3bc 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -1,6 +1,6 @@
 (The MIT License)
 
-Copyright (c) 2014-2023 Yegor Bugayenko
+Copyright (c) 2014-2024 Yegor Bugayenko
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the 'Software'), to deal
diff --git a/Rakefile b/Rakefile
index 3481206..3ec038d 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/assets/puzzles.xsd b/assets/puzzles.xsd
index a31ec44..82e272d 100644
--- a/assets/puzzles.xsd
+++ b/assets/puzzles.xsd
@@ -2,7 +2,7 @@
 <!--
 (The MIT License)
 
-Copyright (c) 2014-2023 Yegor Bugayenko
+Copyright (c) 2014-2024 Yegor Bugayenko
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the 'Software'), to deal
diff --git a/assets/puzzles.xsl b/assets/puzzles.xsl
index e5fcbdc..b727b10 100644
--- a/assets/puzzles.xsl
+++ b/assets/puzzles.xsl
@@ -2,7 +2,7 @@
 <!--
 (The MIT License)
 
-Copyright (c) 2014-2023 Yegor Bugayenko
+Copyright (c) 2014-2024 Yegor Bugayenko
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the 'Software'), to deal
diff --git a/bin/pdd b/bin/pdd
index aa15b88..d4d30df 100755
--- a/bin/pdd
+++ b/bin/pdd
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/features/step_definitions/steps.rb b/features/step_definitions/steps.rb
index fd97516..fd44afc 100644
--- a/features/step_definitions/steps.rb
+++ b/features/step_definitions/steps.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/features/support/env.rb b/features/support/env.rb
index 779e51f..e236d02 100644
--- a/features/support/env.rb
+++ b/features/support/env.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd.rb b/lib/pdd.rb
index 7da93fd..3dcea96 100644
--- a/lib/pdd.rb
+++ b/lib/pdd.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -30,7 +30,7 @@
 
 # PDD main module.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 module PDD
   # If it breaks.
diff --git a/lib/pdd/puzzle.rb b/lib/pdd/puzzle.rb
index 78b114e..61aa328 100644
--- a/lib/pdd/puzzle.rb
+++ b/lib/pdd/puzzle.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/rule/duplicates.rb b/lib/pdd/rule/duplicates.rb
index a386ed8..30f7142 100644
--- a/lib/pdd/rule/duplicates.rb
+++ b/lib/pdd/rule/duplicates.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/rule/estimates.rb b/lib/pdd/rule/estimates.rb
index 2673a2a..0126828 100644
--- a/lib/pdd/rule/estimates.rb
+++ b/lib/pdd/rule/estimates.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/rule/roles.rb b/lib/pdd/rule/roles.rb
index df4eb0b..3bf6e71 100644
--- a/lib/pdd/rule/roles.rb
+++ b/lib/pdd/rule/roles.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/rule/text.rb b/lib/pdd/rule/text.rb
index 1b3898e..4f08179 100644
--- a/lib/pdd/rule/text.rb
+++ b/lib/pdd/rule/text.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/source.rb b/lib/pdd/source.rb
index f3da023..98275c5 100644
--- a/lib/pdd/source.rb
+++ b/lib/pdd/source.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/sources.rb b/lib/pdd/sources.rb
index 436ce4f..baf0e83 100644
--- a/lib/pdd/sources.rb
+++ b/lib/pdd/sources.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/lib/pdd/version.rb b/lib/pdd/version.rb
index 5c9c97b..fdd3383 100644
--- a/lib/pdd/version.rb
+++ b/lib/pdd/version.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -20,7 +20,7 @@
 
 # PDD main module.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 module PDD
   VERSION = '0.0.0'.freeze
diff --git a/pdd.gemspec b/pdd.gemspec
index fd9582f..6551664 100644
--- a/pdd.gemspec
+++ b/pdd.gemspec
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/test/test__helper.rb b/test/test__helper.rb
index 2212d59..f1610ae 100644
--- a/test/test__helper.rb
+++ b/test/test__helper.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/test/test_duplicates.rb b/test/test_duplicates.rb
index adbba01..9185f72 100644
--- a/test/test_duplicates.rb
+++ b/test/test_duplicates.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -24,7 +24,7 @@
 
 # PDD::Rule::MaxDuplicates class test.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestMaxDuplicates < Minitest::Test
   def test_max_duplicates
diff --git a/test/test_estimates.rb b/test/test_estimates.rb
index 9fdc9b1..957f18b 100644
--- a/test/test_estimates.rb
+++ b/test/test_estimates.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -24,7 +24,7 @@
 
 # PDD::Rule::Estimate module tests.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestEstimates < Minitest::Test
   def test_min
diff --git a/test/test_many.rb b/test/test_many.rb
index 0b56d3a..57adb3c 100644
--- a/test/test_many.rb
+++ b/test/test_many.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -25,7 +25,7 @@
 
 # Test many puzzles to make sure their IDs are correct.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestMany < Minitest::Test
   def test_parsing
diff --git a/test/test_pdd.rb b/test/test_pdd.rb
index 52f7aeb..d7408eb 100644
--- a/test/test_pdd.rb
+++ b/test/test_pdd.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -26,7 +26,7 @@
 
 # PDD main module test.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestPDD < Minitest::Test
   def test_basic
diff --git a/test/test_roles.rb b/test/test_roles.rb
index 9530bdd..92c466d 100644
--- a/test/test_roles.rb
+++ b/test/test_roles.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -24,7 +24,7 @@
 
 # PDD::Rule::Role module tests.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestRoles < Minitest::Test
   def test_incorrect_role
diff --git a/test/test_source.rb b/test/test_source.rb
index 1c5f8ea..18433e4 100644
--- a/test/test_source.rb
+++ b/test/test_source.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -26,7 +26,7 @@
 
 # Source test.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestSource < Minitest::Test
   def test_parsing
diff --git a/test/test_source_todo.rb b/test/test_source_todo.rb
index 4b29786..cdd861e 100644
--- a/test/test_source_todo.rb
+++ b/test/test_source_todo.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
diff --git a/test/test_sources.rb b/test/test_sources.rb
index f17f2ba..e7cc11f 100644
--- a/test/test_sources.rb
+++ b/test/test_sources.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -26,7 +26,7 @@
 
 # Sources test.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestSources < Minitest::Test
   def test_iterator
diff --git a/test/test_text.rb b/test/test_text.rb
index 6c5560b..d33a89e 100644
--- a/test/test_text.rb
+++ b/test/test_text.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal
@@ -24,7 +24,7 @@
 
 # PDD::Rule::Text module tests.
 # Author:: Yegor Bugayenko (yegor256@gmail.com)
-# Copyright:: Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright:: Copyright (c) 2014-2024 Yegor Bugayenko
 # License:: MIT
 class TestText < Minitest::Test
   def test_min_words
diff --git a/utils/glob.rb b/utils/glob.rb
index 834da4a..15737a1 100644
--- a/utils/glob.rb
+++ b/utils/glob.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2014-2023 Yegor Bugayenko
+# Copyright (c) 2014-2024 Yegor Bugayenko
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the 'Software'), to deal