diff --git a/ChangeLog b/ChangeLog
index 70c6f3439a..15fb709d13 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Feb 25 23:02:55 2007  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/test/unit/autorunner.rb (Test::Unit::AutoRunner::initialize):
+	  Initialize @workdir properly to silence a warning under -w.
+	  Submitted by <tommy at tmtm.org> in [ruby-dev:30400].
+
 Sun Feb 25 02:47:43 2007  Akinori MUSHA  <knu@iDaemons.org>
 
 	* defines.h: Pull the RUBY_MBCHAR_MAXSIZE definition from trunk,
diff --git a/lib/test/unit/autorunner.rb b/lib/test/unit/autorunner.rb
index dadf080d12..86c9b12940 100644
--- a/lib/test/unit/autorunner.rb
+++ b/lib/test/unit/autorunner.rb
@@ -81,6 +81,7 @@ module Test
         @filters = []
         @to_run = []
         @output_level = UI::NORMAL
+        @workdir = nil
         yield(self) if(block_given?)
       end