diff --git a/invid-conv b/invid-conv
index c16f39a..97d9c60 100755
--- a/invid-conv
+++ b/invid-conv
@@ -25,6 +25,16 @@
 YT_URL="$1"
 INVID_BASE="${INVID_BASE:-https://inv.nadeko.net}"
 
+if [ $# -ne 1 ]
+then
+	>&2 echo "Usage: $0 <url>"
+	exit 1
+elif [ "$1" = "-h" ]
+then
+	echo "Usage: $0 <url>"
+	exit 0
+fi
+
 if [[ $YT_URL == *"youtu.be"* ]]
 then
 	INVID_URL="${INVID_BASE}/watch?v=${YT_URL##*/}"