diff --git a/Lib/test/test_msilib.py b/Lib/test/test_msilib.py
index fa0be58..f9bd0da 100644
--- a/Lib/test/test_msilib.py
+++ b/Lib/test/test_msilib.py
@@ -87,6 +87,7 @@
         db, db_path = init_database()
         self.addCleanup(unlink, db_path)
         self.addCleanup(db.Close)
+        self.addCleanup(msilib._directories.clear)
         feature = msilib.Feature(db, 0, 'Feature', 'A feature', 'Python')
         cab = msilib.CAB('CAB')
         dir = msilib.Directory(db, cab, None, TESTFN, 'TARGETDIR',