diff --git a/ChangeLog b/ChangeLog
index cc2c57ff43..c6939c52a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jan 10 21:03:05 2013 TAKANO `takano32' Mitsuhiro <tak@no32.tk>
+
+	* cont.c: define FIBER_USE_NATIVE as 0 in ia64.
+
 Thu Jan 10 19:39:05 2013  TAKANO `takano32' Mitsuhiro <tak@no32.tk>
 
 	* thread.c: fix RB_GC_SAVE_MACHINE_REGISTER_STACK define for ia64.
diff --git a/cont.c b/cont.c
index 43a60fa149..9b43480dd3 100644
--- a/cont.c
+++ b/cont.c
@@ -15,7 +15,7 @@
 #include "gc.h"
 #include "eval_intern.h"
 
-#if ((defined(_WIN32) && _WIN32_WINNT >= 0x0400) || (defined(HAVE_GETCONTEXT) && defined(HAVE_SETCONTEXT))) && !defined(__NetBSD__) && !defined(__sun) && !defined(FIBER_USE_NATIVE)
+#if ((defined(_WIN32) && _WIN32_WINNT >= 0x0400) || (defined(HAVE_GETCONTEXT) && defined(HAVE_SETCONTEXT))) && !defined(__NetBSD__) && !defined(__sun) && !defined(__ia64) && !defined(FIBER_USE_NATIVE)
 #define FIBER_USE_NATIVE 1
 
 /* FIBER_USE_NATIVE enables Fiber performance improvement using system