diff --git a/ChangeLog b/ChangeLog
index 44405ab7b7..590c9248c5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Mar 12 13:52:00 2010  Kenta Murata  <mrkn@mrkn.jp>
+
+	* tool/compile_prelude.rb: TMP_RUBY_PREFIX should replace
+	  rubylibprefix but not prefix.
+
 Fri Mar 12 09:43:11 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* complex.c (f_signbit): remove condition for signbit because
diff --git a/tool/compile_prelude.rb b/tool/compile_prelude.rb
index 93a6dd9cf0..d13670d955 100755
--- a/tool/compile_prelude.rb
+++ b/tool/compile_prelude.rb
@@ -48,7 +48,7 @@ class Prelude
         key = $1
         unless @mkconf
           require './rbconfig'
-          @mkconf = RbConfig::MAKEFILE_CONFIG.merge('prefix'=>'#{TMP_RUBY_PREFIX}')
+          @mkconf = RbConfig::MAKEFILE_CONFIG.merge('rubylibprefix'=>'#{TMP_RUBY_PREFIX}')
         end
         if RbConfig::MAKEFILE_CONFIG.has_key? key
           val = RbConfig.expand("$(#{key})", @mkconf)