script/public-inbox-index | 3 +++

diff --git a/script/public-inbox-index b/script/public-inbox-index
index 73ca29537b4feae1d44e1f636d115ac00fdb2d9f..9e0907be554815c7fe5bd6b1703721781bfe93ab 100755
--- a/script/public-inbox-index
+++ b/script/public-inbox-index
@@ -42,6 +42,9 @@ 		help|?))
 	or die "bad command-line args\n$usage";
 if ($opt->{help}) { print $help; exit 0 };
 die "--jobs must be >= 0\n" if defined $opt->{jobs} && $opt->{jobs} < 0;
+if ($opt->{xapianonly} && !$opt->{reindex}) {
+	die "--xapian-only requires --reindex\n";
+}
 
 # require lazily to speed up --help
 require PublicInbox::Admin;