diff --git a/sample/test.rb b/sample/test.rb
index 30319c385e..82b159a7b7 100644
--- a/sample/test.rb
+++ b/sample/test.rb
@@ -1191,7 +1191,7 @@ File.unlink "script_tmp" or `/bin/rm -f "script_tmp"`
 File.unlink "script_tmp.bak" or `/bin/rm -f "script_tmp.bak"`
 
 $bad = false
-if (dir = File.dirname(File.dirname(dir))) == '.'
+if (dir = File.dirname(File.dirname($0))) == '.'
   dir = ""
 else
   dir << "/"