diff --git a/bin/start_service.sh b/bin/start_service.sh
index 79ef03f..a2d2f85 100755
--- a/bin/start_service.sh
+++ b/bin/start_service.sh
@@ -3,9 +3,6 @@
 SVC_NAME=$1
 set --
 
-# TODO: remove?
-# PSI_FACILITY=SLS
-
 SERVICES_DIR=/sls/bd/hla/${AGEBD_ENV}/services
 SVC_NAME_LOWER=${SVC_NAME,,}
 SVC_NAME_LOWER_UNDERSCORES="${SVC_NAME_LOWER//-/_}"
@@ -14,6 +11,12 @@ SVC_DIR=${SERVICES_DIR}/${SVC_NAME_LOWER}
 # gfa_12_epics.sh died on the 16.04.2026 due to required AFS write access
 #. /etc/profile.d/gfa_12_epics.sh
 #. /sls/bd/exchange/BeamData/user/felix/workarounds/epicsRHEL8.rc  # temporary fix
+
+# cas_12_epics.sh can only fall back to the CA gateway when its broadcast-address
+# auto-detection fails (e.g. non-accelerator-network hosts) if PSI_GFA_FACILITY is
+# set; systemd --user units don't inherit it from an interactive login shell so we need 
+# to set PSI_GFA_FACILITY=SLS explicitely.
+export PSI_GFA_FACILITY=SLS
 . /etc/profile.d/cas_12_epics.sh
 
 if [ "${AGEBD_ENV}" = "dev" ]; then