diff --git a/ext/json/json.gemspec b/ext/json/json.gemspec
index f4b2ae791dabbe..9cd4ceee2313f3 100644
--- a/ext/json/json.gemspec
+++ b/ext/json/json.gemspec
@@ -1,5 +1,3 @@
-# -*- encoding: utf-8 -*-
-
 Gem::Specification.new do |s|
   s.name = "json"
   s.version = File.read(File.expand_path('../VERSION', __FILE__)).chomp
diff --git a/test/json/json_encoding_test.rb b/test/json/json_encoding_test.rb
index 68a058f7d06e94..ac485e2ac18379 100644
--- a/test/json/json_encoding_test.rb
+++ b/test/json/json_encoding_test.rb
@@ -1,4 +1,3 @@
-# encoding: utf-8
 #frozen_string_literal: false
 require_relative 'test_helper'
 
diff --git a/test/json/json_generator_test.rb b/test/json/json_generator_test.rb
index 09e56e53ecf8d5..526bb8c1febd2c 100755
--- a/test/json/json_generator_test.rb
+++ b/test/json/json_generator_test.rb
@@ -1,5 +1,4 @@
 #!/usr/bin/env ruby
-# encoding: utf-8
 # frozen_string_literal: false
 
 require_relative 'test_helper'
diff --git a/test/json/ractor_test.rb b/test/json/ractor_test.rb
index 2b4115b01f5453..ba9bf7a7f6d8a7 100644
--- a/test/json/ractor_test.rb
+++ b/test/json/ractor_test.rb
@@ -1,4 +1,3 @@
-# encoding: utf-8
 # frozen_string_literal: false
 
 require_relative 'test_helper'