diff --git a/ChangeLog b/ChangeLog
index 2700d4e3d7..5788cbe039 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat May 29 12:56:09 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* encoding.c (rb_filesystem_encindex): avoid infinite require
+	  loop. [ruby-core:30467]
+
 Sat May 29 12:05:51 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/rdoc/rdoc.rb (RDoc#read_file_contents): take care of BOM.
diff --git a/encoding.c b/encoding.c
index 001762221f..83607d5103 100644
--- a/encoding.c
+++ b/encoding.c
@@ -1160,7 +1160,7 @@ rb_filesystem_encindex(void)
 {
     int idx = rb_enc_registered("filesystem");
     if (idx < 0)
-	idx = enc_set_filesystem_encoding();
+	idx = rb_ascii8bit_encindex();
     return idx;
 }