diff --git a/ChangeLog b/ChangeLog
index 9ac85cb2ed..37f02112fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Nov 26 11:40:11 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* vm_dump.c (dump_thread): get only required rights of the target
+	  thread because THREAD_ALL_ACCESS causes an access error on XP.
+	  reported by Masaya TARUI via IRC.
+
 Fri Nov 26 11:09:07 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* vm_dump.c (dump_thread): show the displacement from the beginning
diff --git a/vm_dump.c b/vm_dump.c
index 60fce89464..452e307473 100644
--- a/vm_dump.c
+++ b/vm_dump.c
@@ -684,7 +684,7 @@ dump_thread(void *arg)
 	SymSetOptions(SYMOPT_UNDNAME | SYMOPT_DEFERRED_LOADS | SYMOPT_DEBUG | SYMOPT_LOAD_LINES);
 	ph = GetCurrentProcess();
 	pSymInitialize(ph, NULL, TRUE);
-	th = pOpenThread(THREAD_ALL_ACCESS, FALSE, tid);
+	th = pOpenThread(THREAD_SUSPEND_RESUME|THREAD_GET_CONTEXT, FALSE, tid);
 	if (th) {
 	    if (SuspendThread(th) != (DWORD)-1) {
 		CONTEXT context;