diff --git a/mkconfig.rb b/mkconfig.rb
index c83e5f8d8f..2e346c15af 100644
--- a/mkconfig.rb
+++ b/mkconfig.rb
@@ -83,7 +83,22 @@ end
 print v_fast, v_others
 print <<EOS
   CONFIG["compile_dir"] = "#{Dir.pwd}"
-  MAKEFILE_CONFIG = CONFIG.dup
+  MAKEFILE_CONFIG = {}
+  CONFIG.each{|k,v| MAKEFILE_CONFIG[k] = v.dup}
+  def Config::expand(val)
+    val.gsub!(/\\$\\(([^()]+)\\)/) do |var|
+      key = $1
+      if CONFIG.key? key
+        "\#{Config::expand(CONFIG[\\\"\#{key}\\\"])}"
+      else
+	var
+      end
+    end
+    val
+  end
+  CONFIG.each_value do |val|
+    Config::expand(val)
+  end
 end
 EOS
 config.close