diff --git a/ChangeLog b/ChangeLog
index e58e95cce3..0f4ab10d62 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Mon Dec  5 14:27:23 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* include/ruby/{subst.h,win32.h}, ext/socket/rubysocket.h: revert
+	  r33876.  [ruby-core:41475] [Bug #5706]
+
+	* ext/socket/extconf.rb: the alternative hack for [Bug #5675].
+
 Mon Dec  5 10:18:45 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* ext/zlib/zlib.c (rb_gzreader_initialize): revert a part of r33937.
diff --git a/ext/socket/extconf.rb b/ext/socket/extconf.rb
index 330ee39c5f..ba180c820e 100644
--- a/ext/socket/extconf.rb
+++ b/ext/socket/extconf.rb
@@ -483,7 +483,9 @@ $distcleanfiles << "constants.h" << "constdefs.*"
 if have_func(test_func)
   have_func("hsterror")
   have_func("getipnodebyname") or have_func("gethostbyname2")
-  have_func("socketpair(0, 0, 0, 0)")
+  if !have_func("socketpair(0, 0, 0, 0)") and have_func("rb_w32_socketpair(0, 0, 0, 0)")
+    $defs << "-Dsocketpair(a,b,c,d)=rb_w32_socketpair((a),(b),(c),(d))"
+  end
   unless have_func("gethostname((char *)0, 0)")
     have_func("uname")
   end
diff --git a/ext/socket/rubysocket.h b/ext/socket/rubysocket.h
index d6f990eed9..3e2f6c9565 100644
--- a/ext/socket/rubysocket.h
+++ b/ext/socket/rubysocket.h
@@ -4,7 +4,6 @@
 #include "ruby/ruby.h"
 #include "ruby/io.h"
 #include "ruby/util.h"
-#include "ruby/subst.h"
 #include "internal.h"
 #include <stdio.h>
 #include <sys/types.h>
diff --git a/include/ruby/subst.h b/include/ruby/subst.h
index 79a5165cfb..1f0e6db5a4 100644
--- a/include/ruby/subst.h
+++ b/include/ruby/subst.h
@@ -16,97 +16,4 @@
 #undef close
 #define close ruby_close
 #endif
-
-#ifdef _WIN32
-#undef inet_ntop
-#define inet_ntop(f,a,n,l)      rb_w32_inet_ntop(f,a,n,l)
-
-#undef accept
-#define accept(s, a, l)		rb_w32_accept(s, a, l)
-
-#undef bind
-#define bind(s, a, l)		rb_w32_bind(s, a, l)
-
-#undef connect
-#define connect(s, a, l)	rb_w32_connect(s, a, l)
-
-#undef select
-#define select(n, r, w, e, t)	rb_w32_select(n, r, w, e, t)
-
-#undef getpeername
-#define getpeername(s, a, l)	rb_w32_getpeername(s, a, l)
-
-#undef getsockname
-#define getsockname(s, a, l)	rb_w32_getsockname(s, a, l)
-
-#undef getsockopt
-#define getsockopt(s, v, n, o, l) rb_w32_getsockopt(s, v, n, o, l)
-
-#undef ioctlsocket
-#define ioctlsocket(s, c, a)	rb_w32_ioctlsocket(s, c, a)
-
-#undef listen
-#define listen(s, b)		rb_w32_listen(s, b)
-
-#undef recv
-#define recv(s, b, l, f)	rb_w32_recv(s, b, l, f)
-
-#undef recvfrom
-#define recvfrom(s, b, l, f, fr, frl) rb_w32_recvfrom(s, b, l, f, fr, frl)
-
-#undef send
-#define send(s, b, l, f)	rb_w32_send(s, b, l, f)
-
-#undef sendto
-#define sendto(s, b, l, f, t, tl) rb_w32_sendto(s, b, l, f, t, tl)
-
-#undef setsockopt
-#define setsockopt(s, v, n, o, l) rb_w32_setsockopt(s, v, n, o, l)
-
-#undef shutdown
-#define shutdown(s, h)		rb_w32_shutdown(s, h)
-
-#undef socket
-#define socket(s, t, p)		rb_w32_socket(s, t, p)
-
-#undef gethostbyaddr
-#define gethostbyaddr(a, l, t)	rb_w32_gethostbyaddr(a, l, t)
-
-#undef gethostbyname
-#define gethostbyname(n)	rb_w32_gethostbyname(n)
-
-#undef gethostname
-#define gethostname(n, l)	rb_w32_gethostname(n, l)
-
-#undef getprotobyname
-#define getprotobyname(n)	rb_w32_getprotobyname(n)
-
-#undef getprotobynumber
-#define getprotobynumber(n)	rb_w32_getprotobynumber(n)
-
-#undef getservbyname
-#define getservbyname(n, p)	rb_w32_getservbyname(n, p)
-
-#undef getservbyport
-#define getservbyport(p, pr)	rb_w32_getservbyport(p, pr)
-
-#undef socketpair
-#define socketpair(a, t, p, s)	rb_w32_socketpair(a, t, p, s)
-
-#undef get_osfhandle
-#define get_osfhandle(h)	rb_w32_get_osfhandle(h)
-
-#undef getcwd
-#define getcwd(b, s)		rb_w32_getcwd(b, s)
-
-#undef getenv
-#define getenv(n)		rb_w32_getenv(n)
-
-#undef rename
-#define rename(o, n)		rb_w32_rename(o, n)
-
-#undef times
-#define times(t)		rb_w32_times(t)
-#endif
-
 #endif
diff --git a/include/ruby/win32.h b/include/ruby/win32.h
index 2bdcbc5318..ea6d3939d0 100644
--- a/include/ruby/win32.h
+++ b/include/ruby/win32.h
@@ -586,6 +586,98 @@ extern char *rb_w32_strerror(int);
 #undef FD_ISSET
 #define FD_ISSET(f, s)		rb_w32_fdisset(f, s)
 
+#ifdef RUBY_EXPORT
+#undef inet_ntop
+#define inet_ntop(f,a,n,l)      rb_w32_inet_ntop(f,a,n,l)
+
+#undef accept
+#define accept(s, a, l)		rb_w32_accept(s, a, l)
+
+#undef bind
+#define bind(s, a, l)		rb_w32_bind(s, a, l)
+
+#undef connect
+#define connect(s, a, l)	rb_w32_connect(s, a, l)
+
+#undef select
+#define select(n, r, w, e, t)	rb_w32_select(n, r, w, e, t)
+
+#undef getpeername
+#define getpeername(s, a, l)	rb_w32_getpeername(s, a, l)
+
+#undef getsockname
+#define getsockname(s, a, l)	rb_w32_getsockname(s, a, l)
+
+#undef getsockopt
+#define getsockopt(s, v, n, o, l) rb_w32_getsockopt(s, v, n, o, l)
+
+#undef ioctlsocket
+#define ioctlsocket(s, c, a)	rb_w32_ioctlsocket(s, c, a)
+
+#undef listen
+#define listen(s, b)		rb_w32_listen(s, b)
+
+#undef recv
+#define recv(s, b, l, f)	rb_w32_recv(s, b, l, f)
+
+#undef recvfrom
+#define recvfrom(s, b, l, f, fr, frl) rb_w32_recvfrom(s, b, l, f, fr, frl)
+
+#undef send
+#define send(s, b, l, f)	rb_w32_send(s, b, l, f)
+
+#undef sendto
+#define sendto(s, b, l, f, t, tl) rb_w32_sendto(s, b, l, f, t, tl)
+
+#undef setsockopt
+#define setsockopt(s, v, n, o, l) rb_w32_setsockopt(s, v, n, o, l)
+
+#undef shutdown
+#define shutdown(s, h)		rb_w32_shutdown(s, h)
+
+#undef socket
+#define socket(s, t, p)		rb_w32_socket(s, t, p)
+
+#undef gethostbyaddr
+#define gethostbyaddr(a, l, t)	rb_w32_gethostbyaddr(a, l, t)
+
+#undef gethostbyname
+#define gethostbyname(n)	rb_w32_gethostbyname(n)
+
+#undef gethostname
+#define gethostname(n, l)	rb_w32_gethostname(n, l)
+
+#undef getprotobyname
+#define getprotobyname(n)	rb_w32_getprotobyname(n)
+
+#undef getprotobynumber
+#define getprotobynumber(n)	rb_w32_getprotobynumber(n)
+
+#undef getservbyname
+#define getservbyname(n, p)	rb_w32_getservbyname(n, p)
+
+#undef getservbyport
+#define getservbyport(p, pr)	rb_w32_getservbyport(p, pr)
+
+#undef socketpair
+#define socketpair(a, t, p, s)	rb_w32_socketpair(a, t, p, s)
+
+#undef get_osfhandle
+#define get_osfhandle(h)	rb_w32_get_osfhandle(h)
+
+#undef getcwd
+#define getcwd(b, s)		rb_w32_getcwd(b, s)
+
+#undef getenv
+#define getenv(n)		rb_w32_getenv(n)
+
+#undef rename
+#define rename(o, n)		rb_w32_rename(o, n)
+
+#undef times
+#define times(t)		rb_w32_times(t)
+#endif
+
 struct tms {
 	long	tms_utime;
 	long	tms_stime;