diff --git a/lib/rdoc/text.rb b/lib/rdoc/text.rb
index a38bb921ad..cf708e6bbd 100644
--- a/lib/rdoc/text.rb
+++ b/lib/rdoc/text.rb
@@ -1,4 +1,3 @@
-# coding: utf-8
 # frozen_string_literal: false
 
 ##
diff --git a/rdoc.gemspec b/rdoc.gemspec
index bd4081a3f1..8aadb510e2 100644
--- a/rdoc.gemspec
+++ b/rdoc.gemspec
@@ -1,4 +1,3 @@
-# -*- encoding: utf-8 -*-
 begin
   require_relative "lib/rdoc"
 rescue LoadError
diff --git a/test/test_rdoc_markup_pre_process.rb b/test/test_rdoc_markup_pre_process.rb
index ceb411c745..be3fdcbef3 100644
--- a/test/test_rdoc_markup_pre_process.rb
+++ b/test/test_rdoc_markup_pre_process.rb
@@ -1,4 +1,3 @@
-# coding: utf-8
 # frozen_string_literal: false
 
 require 'rdoc/test_case'
diff --git a/test/test_rdoc_parser_ruby.rb b/test/test_rdoc_parser_ruby.rb
index cda407ed51..5a13cad480 100644
--- a/test/test_rdoc_parser_ruby.rb
+++ b/test/test_rdoc_parser_ruby.rb
@@ -1,4 +1,3 @@
-# coding: utf-8
 # frozen_string_literal: false
 
 require 'rdoc/test_case'
diff --git a/test/test_rdoc_text.rb b/test/test_rdoc_text.rb
index 2eb5ad69c7..7a125854b5 100644
--- a/test/test_rdoc_text.rb
+++ b/test/test_rdoc_text.rb
@@ -1,4 +1,3 @@
-# coding: utf-8
 # frozen_string_literal: false
 
 require 'rdoc/test_case'