diff --git a/arpspoof/rootfs/scripts/99-run.sh b/arpspoof/rootfs/scripts/99-run.sh
index 0a0c77d51..9011010d1 100644
--- a/arpspoof/rootfs/scripts/99-run.sh
+++ b/arpspoof/rootfs/scripts/99-run.sh
@@ -1,7 +1,10 @@
 #!/usr/bin/env bashio
 
+# Autodefine if not defined
+if [ -z INTERFACE_NAME ]; then
 INTERFACE_NAME=$(ip route get 8.8.8.8 | sed -nr 's/.*dev ([^\ ]+).*/\1/p')
-bashio::log.blue "INTERFACE_NAME=$INTERFACE_NAME"
+bashio::log.blue "Autodetection : INTERFACE_NAME=$INTERFACE_NAME"
+fi
 
 bashio::log.info "Starting..."
 /usr/bin/python3 /opt/arpspoof/arpspoof.py