diff --git a/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py b/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py
index da40e95b17c330a8eee6f0956de14ef8c4d8ae78..305607385c03de5c4893c67af41b55e397292ac0 100644
--- a/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py
+++ b/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py
@@ -42,6 +42,7 @@ class SubtaskState(AbstractChoice):
         DEFINED = "defined"
         SCHEDULING = "scheduling"
         SCHEDULED = "scheduled"
+        UNSCHEDULING = "unscheduling"
         QUEUEING = "queueing"
         QUEUED = "queued"
         STARTING = "starting"