diff --git a/firewall/firewall-add b/firewall/firewall-add
index 5b794a8..a08633c 100755
--- a/firewall/firewall-add
+++ b/firewall/firewall-add
@@ -114,7 +114,11 @@ name_resolver() {
 			for D_IP in `echo $UP` ; 
 			do
 				DNS_IP=$(docker inspect $D_IP -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}');	
-				APP_IP="$APP_IP $DNS_IP";
+				if [ "$APP_IP" == "" ]; then
+					APP_IP="$DNS_IP";
+				else
+					APP_IP="$APP_IP $DNS_IP";
+				fi;
 				echo "APP_IP: "$APP_IP;
 			done
 		else