diff --git a/ChangeLog b/ChangeLog
index 590c9248c5..4004c0c5e4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Mar 12 17:36:35 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* lib/webrick/httpservlet/cgihandler.rb
+	  (WEBrick::HTTPServlet::CGIHandler#do_GET):
+	  set binary mode for tempfile.
+	  http://pc12.2ch.net/test/read.cgi/tech/1265467681/286
+
 Fri Mar 12 13:52:00 2010  Kenta Murata  <mrkn@mrkn.jp>
 
 	* tool/compile_prelude.rb: TMP_RUBY_PREFIX should replace
diff --git a/lib/webrick/httpservlet/cgihandler.rb b/lib/webrick/httpservlet/cgihandler.rb
index 7ba2d50860..1976ae6948 100644
--- a/lib/webrick/httpservlet/cgihandler.rb
+++ b/lib/webrick/httpservlet/cgihandler.rb
@@ -32,9 +32,9 @@ module WEBrick
         status = -1
 
         cgi_in = IO::popen(@cgicmd, "wb")
-        cgi_out = Tempfile.new("webrick.cgiout.", @tempdir)
+        cgi_out = Tempfile.new("webrick.cgiout.", @tempdir, mode: IO::BINARY)
         cgi_out.set_encoding("ASCII-8BIT")
-        cgi_err = Tempfile.new("webrick.cgierr.", @tempdir)
+        cgi_err = Tempfile.new("webrick.cgierr.", @tempdir, mode: IO::BINARY)
         cgi_err.set_encoding("ASCII-8BIT")
         begin
           cgi_in.sync = true