diff --git a/ChangeLog b/ChangeLog
index 4c3f8f1094..e130685673 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Fri Jun  6 20:58:25 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/Makefile.sub (COMMON_HEADERS): include ws2tcpip.h.
+
+	* ext/socket/addrinfo.h (addrinfo, getaddrinfo, getnameinfo,
+	  freehostent, freeaddrinfo): undef before define because these are
+	  macros in some versions of Windows SDK.
+
 Fri Jun  6 20:13:01 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/setup.mak: maybe commit miss.
diff --git a/ext/socket/addrinfo.h b/ext/socket/addrinfo.h
index a22615ee00..e93adafba6 100644
--- a/ext/socket/addrinfo.h
+++ b/ext/socket/addrinfo.h
@@ -61,10 +61,15 @@
 #undef NI_NUMERICSERV
 #undef NI_DGRAM
 
+#undef addrinfo
 #define addrinfo addrinfo__compat
+#undef getaddrinfo
 #define getaddrinfo getaddrinfo__compat
+#undef getnameinfo
 #define getnameinfo getnameinfo__compat
+#undef freehostent
 #define freehostent freehostent__compat
+#undef freeaddrinfo
 #define freeaddrinfo freeaddrinfo__compat
 
 #ifndef __P
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index 972e6933f5..1301d86fff 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -249,7 +249,7 @@ COMMON_MACROS = WIN32_LEAN_AND_MEAN WIN32
 !if !defined(USE_WINSOCK2)
 COMMON_HEADERS = winsock.h
 !else
-COMMON_HEADERS = winsock2.h
+COMMON_HEADERS = winsock2.h ws2tcpip.h
 !endif
 COMMON_HEADERS = $(COMMON_HEADERS) windows.h
 !endif