diff --git a/ChangeLog b/ChangeLog
index 8b2fdfbacc..2516b5e939 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Sep 12 19:08:58 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* win32/win32.c (rb_w32_dup2): should return the new fd on
+	  success, while msvcrt returns 0 wrongly.
+
 Sat Sep 12 18:14:11 2015  Shugo Maeda  <shugo@ruby-lang.org>
 
 	* lib/net/ftp.rb (parse_mlsx_entry, mlst) raise an FTPProtoError
diff --git a/win32/win32.c b/win32/win32.c
index 11292a16cc..32e77c01e4 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -5934,8 +5934,9 @@ rb_w32_dup2(int oldfd, int newfd)
 
     if (oldfd == newfd) return newfd;
     ret = dup2(oldfd, newfd);
+    if (ret < 0) return ret;
     set_new_std_fd(newfd);
-    return ret;
+    return newfd;
 }
 
 /* License: Ruby's */