diff --git a/ChangeLog b/ChangeLog
index 2b9f053fb1..94d2422ec9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Feb  2 18:15:12 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/socket/socket.c: turn on do_not_reverse_lookup by default,
+	  which has been reverted in r9880 probably unintentionally,
+	  according to matz.  [ruby-core:24530]
+
 Tue Feb  2 14:30:27 2010  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* enum.c (enum_each_entry): new method #each_entry to pack values
diff --git a/ext/socket/init.c b/ext/socket/init.c
index b143dccd5f..d744f8c559 100644
--- a/ext/socket/init.c
+++ b/ext/socket/init.c
@@ -28,7 +28,7 @@ VALUE rb_eSocket;
 VALUE rb_cSOCKSSocket;
 #endif
 
-int rsock_do_not_reverse_lookup = 0;
+int rsock_do_not_reverse_lookup = 1;
 
 void
 rsock_raise_socket_error(const char *reason, int error)