diff --git a/subcmds/sync.py b/subcmds/sync.py
index c0310c56c..41b8bb038 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -2582,6 +2582,7 @@ later is required to fix a server side protocol bug.
                                 callback=callback,
                                 output=pm,
                                 chunksize=1,
+                                initializer=self.InitWorker,
                             ):
                                 err_event.set()