diff --git a/README.backup.md b/README.backup.md
index 537faba..7da32c2 100644
--- a/README.backup.md
+++ b/README.backup.md
@@ -87,8 +87,10 @@ read-only checks:
 
 1. the files `backup.sh` needs (encryption key, exclude list) exist;
 2. `PBS_SERVER:PBS_PORT` is reachable on TCP;
-3. an authenticated API round-trip succeeds (it lists existing snapshots for
-   this host on the PBS — nothing is written).
+3. an authenticated API round-trip succeeds — it confirms the token works *and*
+   that the namespace `BACKUP_NS` actually exists on the server (a missing
+   namespace is reported explicitly, so a new host fails here until its
+   namespace has been created: `proxmox-backup-client namespace create <ns>`).
 
 It prints a `[ok]` per check and exits 0 on success, 1 on failure:
 
diff --git a/check-connection.sh b/check-connection.sh
index e2d35b5..80d0c34 100755
--- a/check-connection.sh
+++ b/check-connection.sh
@@ -8,7 +8,6 @@ source "$SCRIPT_DIR/backup.env"
 # ==============================================================================
 # CONNECTION CHECK
 # ==============================================================================
-BACKUP_LABEL="${HOSTNAME}-root"
 EXCLUDE_FILE="/opt/backup/exclude"
 
 fail() {
@@ -33,17 +32,20 @@ fi
 echo "[ok] TCP connection to ${PBS_SERVER}:${PBS_PORT}"
 echo
 
-# 3. Authenticated round-trip: list existing snapshots for this host
-if ! SNAP_OUT="$(timeout 30 proxmox-backup-client snapshot list "host/${BACKUP_LABEL}" --ns "$BACKUP_NS" 2>&1)"; then
-    echo "$SNAP_OUT" >&2
+# 3. Authenticated round-trip + namespace existence: list backups in our namespace
+if ! LIST_OUT="$(timeout 30 proxmox-backup-client list --ns "$BACKUP_NS" 2>&1)"; then
+    if echo "$LIST_OUT" | grep -q "ENOENT"; then
+        fail "namespace '${BACKUP_NS}' does not exist on ${PBS_SERVER} — create it, or point BACKUP_NS at an existing namespace"
+    fi
+    echo "$LIST_OUT" >&2
     fail "authenticated request failed — check PBS_AUTH_ID / PBS_PASSWORD in backup.env"
 fi
-echo "[ok] authentication + API round-trip to the server"
-if [ -n "$SNAP_OUT" ]; then
-    echo "existing snapshots for ${BACKUP_LABEL}:"
-    echo "$SNAP_OUT"
+echo "[ok] authentication + API round-trip to the server (namespace ${BACKUP_NS} exists)"
+if [ -n "$LIST_OUT" ]; then
+    echo "existing backups in namespace ${BACKUP_NS}:"
+    echo "$LIST_OUT"
 else
-    echo "    (none yet for ${BACKUP_LABEL} — the first backup has not run)"
+    echo "    (no backups there yet — the first one has not run)"
 fi
 
 echo