diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index 8edb9eb..fe186fa 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -54,6 +54,7 @@
 
     def setUp(self):
         self._path = test_support.TESTFN
+        self._delete_recursively(self._path)
         self._box = self._factory(self._path)
 
     def tearDown(self):