diff --git a/crdt-sync/tool/_seeded_apps.py b/crdt-sync/tool/_seeded_apps.py
index c885031..250b581 100644
--- a/crdt-sync/tool/_seeded_apps.py
+++ b/crdt-sync/tool/_seeded_apps.py
@@ -43,4 +43,7 @@ DEFAULT_APPS: Final = (
     # timer is headless and it has no session of its own to inherit, so
     # without this a day marked on the phone never reaches the PC.
     "freedays",
+    # The daily RTDB backup (~/src/dufs-cloud/firebase_backup). A headless
+    # user timer with its own session, so it never races an app's token file.
+    "firebase_backup",
 )