diff --git a/ChangeLog b/ChangeLog
index 903b04124a..7243c0e17e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,13 @@
+Sun Apr 11 08:56:44 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* lib/rdoc/rdoc.rb (setup_output_dir): compare by Time#to_i.
+	  Cached created time doesn't have fractinal times,
+	  but FileStat#mtime has; so rdoc almost alway judged files
+	  are updated.
+
 Sun Apr 11 07:40:48 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
-	* lib/rdoc/rdoc.rb (setup_output_dir): fix typo.
+	* lib/rdoc/rdoc.rb (setup_output_dir): fix typo. [ruby-core:29415]
 
 Sun Apr 11 07:01:41 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
diff --git a/lib/rdoc/rdoc.rb b/lib/rdoc/rdoc.rb
index 9dd795383f..ed25d4c796 100644
--- a/lib/rdoc/rdoc.rb
+++ b/lib/rdoc/rdoc.rb
@@ -227,7 +227,7 @@ class RDoc::RDoc
       case type = stat.ftype
       when "file" then
         next if last_created = @last_created[rel_file_name] and
-                stat.mtime <= last_created
+                stat.mtime.to_i <= last_created.to_i
 
         if force_doc or RDoc::Parser.can_parse(rel_file_name) then
           file_list << rel_file_name.sub(/^\.\//, '')