lib/PublicInbox/Over.pm | 1 +

diff --git a/lib/PublicInbox/Over.pm b/lib/PublicInbox/Over.pm
index f34e7fc1cb23e10630ea3ab9334a1b4b47e61824..51284601bfc34fbb080ec8bfec5d1af01593e45b 100644
--- a/lib/PublicInbox/Over.pm
+++ b/lib/PublicInbox/Over.pm
@@ -275,6 +275,7 @@ 	[ map {
 		my $r = $_;
 		$eidx_key_sth->execute($r->[0]);
 		my $eidx_key = $eidx_key_sth->fetchrow_array;
+		$eidx_key //= "missing://ibx_id=$r->[0]";
 		"$eidx_key:$r->[1]:".unpack('H*', $r->[2]);
 	} @$rows ];
 }