diff --git a/koans/about_proxy_object_project.rb b/koans/about_proxy_object_project.rb
index ae9a89e71..39929d283 100644
--- a/koans/about_proxy_object_project.rb
+++ b/koans/about_proxy_object_project.rb
@@ -24,6 +24,10 @@ def method_missing(method_name, *args, &block)
     @messages << method_name
     @object.send(method_name, *args, &block)
   end
+
+  def called?(method_name)
+    return @messages.include?(method_name)
+  end
 end
 
 # The proxy object should pass the following Koan: