diff --git a/ChangeLog b/ChangeLog
index c655dacd9e..136220cc9a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Sun Dec 14 18:46:48 2003  WATANABE Hirofumi  <eban@ruby-lang.org>
+
+	* ext/socket/socket.c (Init_socket): IPv6 is not supported although
+	  AF_INET6 is defined on MinGW.
+
+	* lib/ipaddr.rb (AF_INET6): workaround in the environment which does
+	  not support IPv6.
+
 Sat Dec 13 18:55:16 2003  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/iconv/charset_alias.rb: preserve original order.
diff --git a/ext/socket/socket.c b/ext/socket/socket.c
index e842603067..8a1825d795 100644
--- a/ext/socket/socket.c
+++ b/ext/socket/socket.c
@@ -2511,10 +2511,10 @@ Init_socket()
     sock_define_const("AF_UNSPEC", AF_UNSPEC);
     sock_define_const("PF_UNSPEC", PF_UNSPEC);
 #endif
-#ifdef AF_INET6
+#ifdef INET6
     sock_define_const("AF_INET6", AF_INET6);
 #endif
-#ifdef PF_INET6
+#ifdef INET6
     sock_define_const("PF_INET6", PF_INET6);
 #endif
 
diff --git a/lib/ipaddr.rb b/lib/ipaddr.rb
index b8befe8499..79ea0d6245 100644
--- a/lib/ipaddr.rb
+++ b/lib/ipaddr.rb
@@ -32,6 +32,18 @@
 
 require 'socket'
 
+unless Socket.const_defined? "AF_INET6"
+  class Socket
+    AF_INET6 = Object.new
+  end
+  class << IPSocket
+    alias getaddress_orig getaddress
+    def getaddress(s)
+      /^::/ =~ s ? s : getaddress_orig(s)
+    end
+  end
+end
+
 # IPAddr provides a set of methods to manipulate an IP address.  Both
 # IPv4 and IPv6 are supported.
 class IPAddr