diff --git a/lib/decent_exposure/mailer.rb b/lib/decent_exposure/mailer.rb
index 3928168..9be47bd 100644
--- a/lib/decent_exposure/mailer.rb
+++ b/lib/decent_exposure/mailer.rb
@@ -9,6 +9,7 @@ def process_action(*args)
           self.params = arg.stringify_keys if arg && Hash === arg
           super
         end
+        ruby2_keywords(:process_action) if respond_to?(:ruby2_keywords, true)
       end
     end
   end