--- configure.ac~	2012-11-03 10:54:07.721850540 +0800
+++ configure.ac	2012-11-03 10:57:40.717246360 +0800
@@ -746,7 +746,7 @@
   rubyecasound_support=no
   ECA_S_RUBY_SITEDIR=""
 else
-  ECA_S_RUBY_SITEDIR="`ruby -e 'require "rbconfig"; include Config; print CONFIG[["sitedir"]] + "/" + CONFIG[["MAJOR"]] + "." + CONFIG[["MINOR"]]'`"
+  ECA_S_RUBY_SITEDIR="`ruby -rrbconfig -e 'print RbConfig::CONFIG[["sitelibdir"]]'`"
 fi
 
 AC_SUBST(ECA_S_RUBY_SITEDIR)