diff --git a/usr/local/share/bastille/convert.sh b/usr/local/share/bastille/convert.sh
index 5a1bf641..f1ccd819 100644
--- a/usr/local/share/bastille/convert.sh
+++ b/usr/local/share/bastille/convert.sh
@@ -76,6 +76,10 @@ while [ "$#" -gt 0 ]; do
     esac
 done
 
+if [ "$#" -lt 1 ] || [ "$#" -gt 2 ]; then
+    usage
+fi
+
 TARGET="${1}"
 CONVERT_RELEASE="${2}"