diff --git a/rake.gemspec b/rake.gemspec
index 911384c46..4d04b9c3e 100644
--- a/rake.gemspec
+++ b/rake.gemspec
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 $LOAD_PATH.unshift File.expand_path('../lib', __FILE__)
 require 'rake/version'