--- a/setup.rb
+++ b/setup.rb
@@ -792,7 +792,7 @@
     else
       require 'rbconfig'
     end
-    ::Config::CONFIG
+    ::RbConfig::CONFIG
   end
 
   def initialize(ardir_root, config)
--- a/pre-setup.rb
+++ b/pre-setup.rb
@@ -5,7 +5,7 @@
 # Modified by Mathieu Blondel for fantasdic
 
 basename = "fantasdic"
-config = Config::CONFIG
+config = RbConfig::CONFIG
 podir = srcdir_root + "/po/"
 
 # Create MO files.