Clear unrequired paramater for incremental field
diff --git a/staffeln/objects/volume.py b/staffeln/objects/volume.py
index eded18e..a4f24f6 100644
--- a/staffeln/objects/volume.py
+++ b/staffeln/objects/volume.py
@@ -21,7 +21,7 @@
         "project_id": sfeild.UUIDField(),
         "volume_id": sfeild.UUIDField(),
         "backup_completed": sfeild.IntegerField(),
-        "incremental": sfeild.BooleanField(nullable=True, default=False),
+        "incremental": sfeild.BooleanField(nullable=True),
         "created_at": ovoo_fields.DateTimeField(),
     }