diff --git a/script/get_config.rb b/script/get_config.rb
index b9b6d6cdb..e27644312 100755
--- a/script/get_config.rb
+++ b/script/get_config.rb
@@ -34,7 +34,7 @@ ARGV.each do |arg|
   var, setting_name = arg.split("=")
   setting_name = var unless setting_name
   setting = AppConfig.send(setting_name)
-  setting = setting.get if setting.is_a?(Configuration::Proxy)
+  setting = setting.get if setting.respond_to?(:_proxy?)
   if var != setting_name
     puts "#{var}=#{setting}"
   else