diff --git a/arpspoof/rootfs/scripts/99-run.sh b/arpspoof/rootfs/scripts/99-run.sh
index 9011010d1..b92412943 100644
--- a/arpspoof/rootfs/scripts/99-run.sh
+++ b/arpspoof/rootfs/scripts/99-run.sh
@@ -2,7 +2,7 @@
 
 # Autodefine if not defined
 if [ -z INTERFACE_NAME ]; then
-INTERFACE_NAME=$(ip route get 8.8.8.8 | sed -nr 's/.*dev ([^\ ]+).*/\1/p')
+export INTERFACE_NAME=$(ip route get 8.8.8.8 | sed -nr 's/.*dev ([^\ ]+).*/\1/p')
 bashio::log.blue "Autodetection : INTERFACE_NAME=$INTERFACE_NAME"
 fi