diff --git a/repo2html b/repo2html
index 1cad669..26643a4 100755
--- a/repo2html
+++ b/repo2html
@@ -126,7 +126,8 @@ done
 
 shift $((OPTIND-1))
 
-test $do_raw || url_root="${1?Missing root URL (for RSS)}"
+url_root="${1}"
+test "$do_raw" -o "$url_root" || { echo 'Missing root URL' >&2; exit 64; }
 
 # default title to repository name (as taken from the directory)
 title="${title:-$( cwarn title $( basename "$path_out" ) )}"