lib/PublicInbox/SearchIdx.pm | 4 ++--

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index c93c9034e9df31d557e516a0199e020264dcdd9c..9550847b784c42d96da03e44688c377d20c1be71 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -8,8 +8,8 @@ # relationships for use by PublicInbox::SearchThread.
 # This writes to the search index.
 package PublicInbox::SearchIdx;
 use strict;
-use warnings;
-use base qw(PublicInbox::Search PublicInbox::Lock);
+use v5.10.1;
+use parent qw(PublicInbox::Search PublicInbox::Lock);
 use PublicInbox::Eml;
 use PublicInbox::InboxWritable;
 use PublicInbox::MID qw/mid_clean mid_mime mids_for_index/;