diff --git a/ChangeLog b/ChangeLog
index 9f749da424..1a5dc2afa4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,10 +8,6 @@ Sun Sep  3 04:40:42 2006  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/socket.c: include arpa/inet.h if available.
 
-Sun Sep  3 04:03:06 2006  Tanaka Akira  <akr@fsij.org>
-
-	* ext/curses/curses.c: define _XOPEN_SOURCE_EXTENDED on HP-UX.
-
 Sat Sep  2 23:59:58 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* string.c (Init_String): undef Symbol#new.
diff --git a/ext/curses/curses.c b/ext/curses/curses.c
index 45118d19fd..9e448bf881 100644
--- a/ext/curses/curses.c
+++ b/ext/curses/curses.c
@@ -28,10 +28,6 @@
 # endif
 # include <curses_colr/curses.h>
 #else
-# if defined(__hpux) && !defined(_XOPEN_SOURCE_EXTENDED)
-/* HP-UX needs _XOPEN_SOURCE_EXTENDED to use getmaxy, etc. */
-#  define _XOPEN_SOURCE_EXTENDED
-# endif
 # include <curses.h>
 # if defined(__bsdi__) || defined(__NetBSD__) || defined(__APPLE__)
 #  if !defined(_maxx)