diff --git a/src/allmydata/test/test_magic_folder.py b/src/allmydata/test/test_magic_folder.py
index 5fca3cba2..0d03e686f 100644
--- a/src/allmydata/test/test_magic_folder.py
+++ b/src/allmydata/test/test_magic_folder.py
@@ -32,7 +32,7 @@ class MagicFolderTestMixin(MagicFolderCLITestMixin, ShouldFailMixin, ReallyEqual
         temp = self.mktemp()
         self.basedir = abspath_expanduser_unicode(temp.decode(get_filesystem_encoding()))
         self.magicfolder = None
-        Downloader.REMOTE_SCAN_INTERVAL = 0
+        self.patch(Downloader, 'REMOTE_SCAN_INTERVAL', 0)
 
     def _get_count(self, name, client=None):
         counters = (client or self.get_client()).stats_provider.get_stats()["counters"]