diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 2904dc0589..d8bc1b525d 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1,5 +1,4 @@
 # -*- coding: us-ascii -*-
-# frozen_string_literal: false
 # frozen-string-literal: false
 # module to create Makefile for extension modules
 # invoke like: ruby -r mkmf extconf.rb
diff --git a/lib/shellwords.rb b/lib/shellwords.rb
index 76aedbc179..0030f0784f 100644
--- a/lib/shellwords.rb
+++ b/lib/shellwords.rb
@@ -1,4 +1,3 @@
-# frozen_string_literal: false
 # frozen-string-literal: true
 ##
 # == Manipulates strings like the UNIX Bourne shell