diff --git a/lib/hashie/mash.rb b/lib/hashie/mash.rb
index 6ab6e9a7..f72633d2 100644
--- a/lib/hashie/mash.rb
+++ b/lib/hashie/mash.rb
@@ -62,7 +62,6 @@ module Hashie
   #   mash.author # => <Mash>
   #
   class Mash < Hash
-    include Hashie::Extensions::PrettyInspect
     include Hashie::Extensions::RubyVersionCheck
     extend Hashie::Extensions::KeyConflictWarning