diff --git a/ChangeLog b/ChangeLog
index b37451f091..e3abd08faf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon May 26 07:15:52 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vm_dump.c (rb_vm_bugreport): rb_make_backtrace has no arguments.
+
 Mon May 26 01:17:54 2008  Tanaka Akira  <akr@fsij.org>
 
 	* test/ruby/envutil.rb (assert_normal_exit): signal description
diff --git a/vm_dump.c b/vm_dump.c
index 5221b449fa..38b8f25eeb 100644
--- a/vm_dump.c
+++ b/vm_dump.c
@@ -571,6 +571,8 @@ thread_dump_state(VALUE self)
     return Qnil;
 }
 
+VALUE rb_make_backtrace(void);
+
 void
 rb_vm_bugreport(void)
 {
@@ -581,7 +583,7 @@ rb_vm_bugreport(void)
 	int i;
 	SDR();
 
-	bt = rb_make_backtrace(th, 0);
+	bt = rb_make_backtrace();
 	if (TYPE(bt) == T_ARRAY)
 	for (i = 0; i < RARRAY_LEN(bt); i++) {
 	    dp(RARRAY_PTR(bt)[i]);