diff --git a/planetstack/hpc_observer/start.sh b/planetstack/hpc_observer/start.sh
index b4df9f5..c24ca3e 100644
--- a/planetstack/hpc_observer/start.sh
+++ b/planetstack/hpc_observer/start.sh
@@ -1 +1,2 @@
-nohup python hpc-backend.py  -C /opt/planetstack/hpc_observer/hpc_observer_config > /dev/null 2>&1 &
+export XOS_DIR=/opt/xos
+nohup python hpc-backend.py  -C $XOS_DIR/hpc_observer/hpc_observer_config > /dev/null 2>&1 &