diff --git a/bin/check b/bin/check
index 8bcb7f2..646491f 100755
--- a/bin/check
+++ b/bin/check
@@ -61,7 +61,7 @@ if [ -n "${PUBLICPORTS}" ]; then
 	for PORT in ${PUBLICPORTS}; do
 		TRIES=5
 		if echo $PORT |grep -q '/udp$'; then
-			NC_OPTS="--udp"
+			NC_OPTS="-u"
 			PORT="$(echo $PORT |sed -e 's,/udp$,,')"
 		else
 			NC_OPTS=""