diff --git a/ChangeLog b/ChangeLog
index 99f497b76e..e59564998b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Oct 21 20:12:19 2008  Tanaka Akira  <akr@fsij.org>
+
+	* lib/test/unit.rb (assert_nothing_raised): set backtrace.
+
 Tue Oct 21 18:17:42 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* ext/zlib/zlib.c: remove obsolete prototype macros.
diff --git a/lib/test/unit.rb b/lib/test/unit.rb
index 0674ad4bfb..57ae020b25 100644
--- a/lib/test/unit.rb
+++ b/lib/test/unit.rb
@@ -82,7 +82,9 @@ module Test
           if ((args.empty? && !e.instance_of?(MiniTest::Assertion)) ||
               args.any? {|a| a.instance_of?(Module) ? e.is_a?(a) : e.class == a })
             msg = message(msg) { "Exception raised:\n<#{mu_pp(e)}>" }
-            assert(false, msg)
+            exc = MiniTest::Assertion.new(msg.call)
+            exc.set_backtrace(e.backtrace)
+            raise exc
           else
             raise
           end