diff --git a/Library/Homebrew/compat.rb b/Library/Homebrew/compat.rb
index 6d164787ce..35bd487de4 100644
--- a/Library/Homebrew/compat.rb
+++ b/Library/Homebrew/compat.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "compat/cask/dsl/version"
diff --git a/Library/Homebrew/compat/cask/dsl/version.rb b/Library/Homebrew/compat/cask/dsl/version.rb
index 107e628eab..f83e8a3e9b 100644
--- a/Library/Homebrew/compat/cask/dsl/version.rb
+++ b/Library/Homebrew/compat/cask/dsl/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Cask
   class DSL
     class Version < ::String