diff --git a/ChangeLog b/ChangeLog
index cedb50a235..b55fffa7ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Aug 13 13:21:58 2007  Tanaka Akira  <akr@fsij.org>
+
+	* lib/open-uri.rb: make ftp passive mode to avoid NAT problem.
+	  [ruby-dev:31377]
+
 Mon Aug 13 05:03:53 2007  Koichi Sasada  <ko1@atdot.net>
 
 	* thread.c (rb_thread_raise): check if target thread is
diff --git a/lib/open-uri.rb b/lib/open-uri.rb
index 37d22a1572..a38d596562 100644
--- a/lib/open-uri.rb
+++ b/lib/open-uri.rb
@@ -743,6 +743,7 @@ module URI
 
       # The access sequence is defined by RFC 1738
       ftp = Net::FTP.open(self.host)
+      ftp.passive = true
       # todo: extract user/passwd from .netrc.
       user = 'anonymous'
       passwd = nil