diff --git a/ChangeLog b/ChangeLog
index 54f1cb5f5f..18cdb865c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jan 27 22:26:25 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* vm_eval.c (rb_backtrace): "circular require" warning was output to
+	  stdout except the first line.  All line is output to stderr now.
+	  [ruby-dev:40147]
+
 Wed Jan 27 00:22:20 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* ext/bigdecimal/bigdecimal.c (BigDecimal_DoDivmod, BigDecimal_mod,
diff --git a/vm_eval.c b/vm_eval.c
index 762453e5fe..ada783da8d 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -1577,7 +1577,7 @@ print_backtrace(void *arg, VALUE file, int line, VALUE method)
 void
 rb_backtrace(void)
 {
-    vm_backtrace_each(GET_THREAD(), -1, print_backtrace, stdout);
+    vm_backtrace_each(GET_THREAD(), -1, print_backtrace, stderr);
 }
 
 VALUE