diff --git a/ChangeLog b/ChangeLog
index d6e14d7735..2e03f7459e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jan 13 21:44:30 2009  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* io.c (io_reopen, rb_io_init_copy): should register fptr to pipe_list
+	  when copying pipe fptr.
+
 Tue Jan 13 21:38:07 2009  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/socket.c (rb_getaddrinfo): use getaddrinfo with GVL if
diff --git a/io.c b/io.c
index 3d615c2daf..1a445df2ef 100644
--- a/io.c
+++ b/io.c
@@ -5259,6 +5259,10 @@ io_reopen(VALUE io, VALUE nfile)
     if (orig->pathv) fptr->pathv = orig->pathv;
     else fptr->pathv = Qnil;
     fptr->finalize = orig->finalize;
+#if defined (__CYGWIN__) || !defined(HAVE_FORK)
+    if (fptr->finalize == pipe_finalize)
+	pipe_add_fptr(fptr);
+#endif
 
     fd = fptr->fd;
     fd2 = orig->fd;
@@ -5410,6 +5414,10 @@ rb_io_init_copy(VALUE dest, VALUE io)
     fptr->lineno = orig->lineno;
     if (!NIL_P(orig->pathv)) fptr->pathv = orig->pathv;
     fptr->finalize = orig->finalize;
+#if defined (__CYGWIN__) || !defined(HAVE_FORK)
+    if (fptr->finalize == pipe_finalize)
+	pipe_add_fptr(fptr);
+#endif
 
     fd = ruby_dup(orig->fd);
     fptr->fd = fd;