diff --git a/ClusterController/QueueMachine.py b/ClusterController/QueueMachine.py
index d281131..6b02292 100644
--- a/ClusterController/QueueMachine.py
+++ b/ClusterController/QueueMachine.py
@@ -4,6 +4,7 @@ class QueueMachineStateFlags: #
 	ALARM=2	# the queue machine is in alarm state (see man qstat) 
 	UNKNOWN=4 # the queue machine is in unknown state because sge_execd cannot be contected (see man qstat)  
 	ERROR=8 # the queue is in error state
+	OBSOLETE=16 # the queue no longer exists but it is still visible because it still contains running jobs 
 
 class QueueMachine:
 	"""