diff --git a/anki/sync.py b/anki/sync.py
index c5425efda..c7c7eb534 100644
--- a/anki/sync.py
+++ b/anki/sync.py
@@ -112,7 +112,7 @@ class SyncTools(object):
 
     def sync(self):
         "Sync two decks locally. Reimplement this for finer control."
-        if not self.prepareSync():
+        if not self.prepareSync(0):
             return
         sums = self.summaries()
         payload = self.genPayload(sums)