lib/PublicInbox/SearchIdxShard.pm | 2 +-

diff --git a/lib/PublicInbox/SearchIdxShard.pm b/lib/PublicInbox/SearchIdxShard.pm
index 20077e08fa2edc13ef17926d7bc55789559f628d..75521b43a4087badcc5daa2bccc5adcd9323956d 100644
--- a/lib/PublicInbox/SearchIdxShard.pm
+++ b/lib/PublicInbox/SearchIdxShard.pm
@@ -97,7 +97,7 @@ 						num blob ds ts mid)}),
 			"\n", $$msgref or die "failed to write shard $!\n";
 	} else {
 		if ($eml) {
-			$$msgref = undef;
+			undef $$msgref;
 		} else { # --xapian-only + --sequential-shard:
 			$eml = PublicInbox::Eml->new($msgref);
 		}