--- extconf.rb.orig	2011-06-12 14:46:03.000000000 +0000
+++ extconf.rb	2011-06-12 14:46:22.000000000 +0000
@@ -50,13 +50,13 @@
 rdoc: docs/doc/index.html
 
 docs/doc/index.html: $(RDOC)
-\t@-(cd docs; rdoc .)
+\t@-(cd docs; ${RUBY_RDOC} .)
 
 ri:
-\t@-(rdoc -r docs/*rb)
+\t@-(${RUBY_RDOC} -r docs/*rb)
 
 ri-site:
-\t@-(rdoc -R docs/*rb)
+\t@-(${RUBY_RDOC} -R docs/*rb)
 
 rd2: html