diff --git a/ChangeLog b/ChangeLog
index 13e9031ed6..1225c8e832 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Feb  2 14:18:20 2009  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/option.c: use INET6 instead of IPV6.
+
 Mon Feb  2 12:47:47 2009  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* ext/socket/{options,raddrinfo}.c: use INET6 instead of AF_INET6 for
diff --git a/ext/socket/option.c b/ext/socket/option.c
index ae6e2dd1c2..96dd0f5903 100644
--- a/ext/socket/option.c
+++ b/ext/socket/option.c
@@ -21,7 +21,7 @@ optname_to_sym(int level, int optname)
         return constant_to_sym(optname, intern_so_optname);
       case IPPROTO_IP:
         return constant_to_sym(optname, intern_ip_optname);
-#ifdef IPV6
+#ifdef INET6
       case IPPROTO_IPV6:
         return constant_to_sym(optname, intern_ipv6_optname);
 #endif