5 files changed, 5 insertions, 0 deletions
diff --git a/ext/tk/sample/tkextlib/tcllib/datefield.rb b/ext/tk/sample/tkextlib/tcllib/datefield.rb
index 3550af7d23..cf77ed5e64 100644
--- a/ext/tk/sample/tkextlib/tcllib/datefield.rb
+++ b/ext/tk/sample/tkextlib/tcllib/datefield.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/ruby
+# frozen_string_literal: false
 
 require 'tk'
 require 'tkextlib/tcllib/datefield'
diff --git a/ext/tk/sample/tkextlib/tcllib/plotdemos1.rb b/ext/tk/sample/tkextlib/tcllib/plotdemos1.rb
index 7f35a3833c..89166c1c30 100644
--- a/ext/tk/sample/tkextlib/tcllib/plotdemos1.rb
+++ b/ext/tk/sample/tkextlib/tcllib/plotdemos1.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/ruby
+# frozen_string_literal: false
 
 require 'tk'
 require 'tkextlib/tcllib/plotchart'
diff --git a/ext/tk/sample/tkextlib/tcllib/plotdemos2.rb b/ext/tk/sample/tkextlib/tcllib/plotdemos2.rb
index cb657a40d8..58c5b1928b 100644
--- a/ext/tk/sample/tkextlib/tcllib/plotdemos2.rb
+++ b/ext/tk/sample/tkextlib/tcllib/plotdemos2.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/ruby
+# frozen_string_literal: false
 
 require 'tk'
 require 'tkextlib/tcllib/plotchart'
diff --git a/ext/tk/sample/tkextlib/tcllib/plotdemos3.rb b/ext/tk/sample/tkextlib/tcllib/plotdemos3.rb
index 66b8fe706a..816e38b6a6 100644
--- a/ext/tk/sample/tkextlib/tcllib/plotdemos3.rb
+++ b/ext/tk/sample/tkextlib/tcllib/plotdemos3.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/ruby
+# frozen_string_literal: false
 
 require 'tk'
 require 'tkextlib/tcllib/plotchart'
diff --git a/ext/tk/sample/tkextlib/tcllib/xyplot.rb b/ext/tk/sample/tkextlib/tcllib/xyplot.rb
index 2aa101efcb..3d71c3bf9f 100644
--- a/ext/tk/sample/tkextlib/tcllib/xyplot.rb
+++ b/ext/tk/sample/tkextlib/tcllib/xyplot.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/ruby
+# frozen_string_literal: false
 
 require 'tk'
 require 'tkextlib/tcllib/plotchart'