diff --git a/clients_protocol/stores.py b/clients_protocol/stores.py
index 3f0966c..d8ed6e5 100644
--- a/clients_protocol/stores.py
+++ b/clients_protocol/stores.py
@@ -40,6 +40,7 @@ class StoreOfferProperty(enum.Enum):
     AUCTION = enum.auto()
     SOLD_OUT = enum.auto()
     DISCOUNT = enum.auto()
+    PRE_ORDER = enum.auto()
 
 
 @dataclasses.dataclass(frozen=True, order=True, slots=True)