diff --git a/libraries/apache.rb b/libraries/apache.rb
index 523e850..6d6308c 100644
--- a/libraries/apache.rb
+++ b/libraries/apache.rb
@@ -1,4 +1,5 @@
-# encoding: utf-8
+# frozen_string_literal: true
+
 # copyright: 2015, Vulcano Security GmbH
 
 class Apache < Inspec.resource(1)