diff --git a/golem_messages/message/tasks.py b/golem_messages/message/tasks.py
index 8ee7007..a4be734 100644
--- a/golem_messages/message/tasks.py
+++ b/golem_messages/message/tasks.py
@@ -581,6 +581,7 @@ class REASON(datastructures.StringEnum):
         InsufficientBalance = enum.auto()
         InsufficientDeposit = enum.auto()  # GNTB deposit too low
         TooShortDeposit = enum.auto()  # GNTB deposit has too short lock
+        OfferCancelled = enum.auto()
 
     @base.verify_slot('task_to_compute', TaskToCompute)
     def deserialize_slot(self, key, value):