diff --git a/ChangeLog b/ChangeLog
index 839461d0fa..13661d96a6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Dec 14 18:18:31 2007  Tanaka Akira  <akr@fsij.org>
+
+	* thread_pthread.ci (native_thread_create): twice the stack size.
+	  512KB is not enough to complete test-all on Debian GNU/Linux on
+	  IA64.
+	  
 Fri Dec 14 16:10:50 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* io.c (rb_f_p): RDoc update.  a patch from murphy <murphy AT rubychan.de>.
diff --git a/thread_pthread.ci b/thread_pthread.ci
index 6004d4aa35..9d5a7d3d79 100644
--- a/thread_pthread.ci
+++ b/thread_pthread.ci
@@ -280,7 +280,7 @@ native_thread_create(rb_thread_t *th)
     }
     else {
 	pthread_attr_t attr;
-	size_t stack_size = 512 * 1024;	/* 512KB */
+	size_t stack_size = 1024 * 1024; /* 1024KB */
 
 #ifdef PTHREAD_STACK_MIN
 	if (stack_size < PTHREAD_STACK_MIN) {