7 files changed, 7 insertions, 0 deletions
diff --git a/ext/tk/sample/tkextlib/bwidget/basic.rb b/ext/tk/sample/tkextlib/bwidget/basic.rb
index 060baf8a6c..6a7bdbc1f6 100644
--- a/ext/tk/sample/tkextlib/bwidget/basic.rb
+++ b/ext/tk/sample/tkextlib/bwidget/basic.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #
 #  basic demo  ---  called from demo.rb
 #
diff --git a/ext/tk/sample/tkextlib/bwidget/demo.rb b/ext/tk/sample/tkextlib/bwidget/demo.rb
index 3eb98818f3..0b5578ca68 100644
--- a/ext/tk/sample/tkextlib/bwidget/demo.rb
+++ b/ext/tk/sample/tkextlib/bwidget/demo.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: false
 require 'tk'
 require 'tkextlib/bwidget'
 
diff --git a/ext/tk/sample/tkextlib/bwidget/dnd.rb b/ext/tk/sample/tkextlib/bwidget/dnd.rb
index b1b1cf60ff..326288bade 100644
--- a/ext/tk/sample/tkextlib/bwidget/dnd.rb
+++ b/ext/tk/sample/tkextlib/bwidget/dnd.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #
 #  dnd demo  ---  called from demo.rb
 #
diff --git a/ext/tk/sample/tkextlib/bwidget/manager.rb b/ext/tk/sample/tkextlib/bwidget/manager.rb
index a59afb8b86..b0371699ad 100644
--- a/ext/tk/sample/tkextlib/bwidget/manager.rb
+++ b/ext/tk/sample/tkextlib/bwidget/manager.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #
 #  manager demo  ---  called from demo.rb
 #
diff --git a/ext/tk/sample/tkextlib/bwidget/select.rb b/ext/tk/sample/tkextlib/bwidget/select.rb
index 3a1a810e14..b32a69d837 100644
--- a/ext/tk/sample/tkextlib/bwidget/select.rb
+++ b/ext/tk/sample/tkextlib/bwidget/select.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #
 #  select demo  ---  called from demo.rb
 #
diff --git a/ext/tk/sample/tkextlib/bwidget/tmpldlg.rb b/ext/tk/sample/tkextlib/bwidget/tmpldlg.rb
index da2c9678c0..1496cbce2f 100644
--- a/ext/tk/sample/tkextlib/bwidget/tmpldlg.rb
+++ b/ext/tk/sample/tkextlib/bwidget/tmpldlg.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #
 #  templdlg demo  ---  called from demo.rb
 #
diff --git a/ext/tk/sample/tkextlib/bwidget/tree.rb b/ext/tk/sample/tkextlib/bwidget/tree.rb
index 9ef6569d16..fbccd0d250 100644
--- a/ext/tk/sample/tkextlib/bwidget/tree.rb
+++ b/ext/tk/sample/tkextlib/bwidget/tree.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #
 #  templdlg demo  ---  called from demo.rb
 #