diff --git a/lib/fileutils.rb b/lib/fileutils.rb
index 7cbc6f4..fa96599 100644
--- a/lib/fileutils.rb
+++ b/lib/fileutils.rb
@@ -85,7 +85,11 @@
 # <tt>:verbose</tt> flags to methods in FileUtils.
 #
 
-require 'rbconfig'
+begin
+  require 'rbconfig'
+rescue LoadError
+  # for make mjit-headers
+end
 
 module FileUtils