diff --git a/ChangeLog b/ChangeLog
index 5dfe3c4e6e..e4dc43b25a 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.
-
 Sun Sep  3 02:34:55 2006  Masatoshi SEKI  <m_seki@mva.biglobe.ne.jp>
 
 	* lib/drb/unix.rb (DRbUNIXSocket#close): don't get path if client mode.
diff --git a/ext/curses/curses.c b/ext/curses/curses.c
index 1476a1976d..9c51a2127f 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)