lib/PublicInbox/Git.pm       | 4 +++-
 lib/PublicInbox/SearchIdx.pm | 1 +

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index f47bc439080749c25100aca9cb1bb0f32b2d7c13..59c274702174f9e165ba30f99b4ed0136b04f67f 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -39,7 +39,7 @@
 sub cat_file {
 	my ($self, $obj, $ref) = @_;
 
-	$self->_bidi_pipe(qw(--batch in out pid));
+	batch_prepare($self);
 	$self->{out}->print($obj, "\n") or fail($self, "write error: $!");
 
 	my $in = $self->{in};
@@ -88,6 +88,8 @@ 	die $cb_err if $cb_err;
 
 	$rv;
 }
+
+sub batch_prepare ($) { _bidi_pipe($_[0], qw(--batch in out pid)) }
 
 sub check {
 	my ($self, $obj) = @_;
diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 6efc1f3fb937ebb17726cdbddbd3defd77c85e4b..0582526e8b1c5b0f0866b39911e1a94d9a3507dc 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -390,6 +390,7 @@ 	my ($self, $opts) = @_;
 	my $tip = $opts->{ref} || 'HEAD';
 	my $reindex = $opts->{reindex};
 	my ($mkey, $last_commit, $lx, $xlog);
+	$self->{git}->batch_prepare;
 	my $xdb = _xdb_acquire($self);
 	$xdb->begin_transaction;
 	do {