Allow default incremental for backward compatible
diff --git a/staffeln/objects/volume.py b/staffeln/objects/volume.py
index 7ca3df5..f365c0d 100644
--- a/staffeln/objects/volume.py
+++ b/staffeln/objects/volume.py
@@ -19,7 +19,7 @@
"project_id": sfeild.UUIDField(),
"volume_id": sfeild.UUIDField(),
"backup_completed": sfeild.IntegerField(),
- "incremental": sfeild.BooleanField(nullable=True),
+ "incremental": sfeild.BooleanField(nullable=True, default=False),
"created_at": ovoo_fields.DateTimeField(),
}