diff --git a/selfdrive/updated.py b/selfdrive/updated.py
index 79b759a906..fc51ae799d 100755
--- a/selfdrive/updated.py
+++ b/selfdrive/updated.py
@@ -240,7 +240,7 @@ def handle_agnos_update() -> None:
 class Updater:
   def __init__(self):
     self.params = Params()
-    self.branches = defaultdict(lambda: None)
+    self.branches = defaultdict(lambda: '')
 
   @property
   def target_branch(self) -> str: