diff --git a/openwrt-add-lte.sh b/openwrt-add-lte.sh
index 5e3a2c7..0be94fe 100755
--- a/openwrt-add-lte.sh
+++ b/openwrt-add-lte.sh
@@ -4,7 +4,8 @@
 if [ $# -ne 2 ]; then
     echo "$0 ip-address interface"
     echo "    ip-address: where to find the OpenWRT device"
-    echo "    interface: which interface (eth3 for instance) is the LTE device"
+    echo "    interface: which interface is the LTE device"
+    echo "        Usually eth1 on VIIRB, eth3 on PIB"
     exit 1
 fi