diff --git a/src/test/recovery/t/055_standby_snapshot_export.pl b/src/test/recovery/t/055_standby_snapshot_export.pl
index 139190cf231..4cf3e78c766 100644
--- a/src/test/recovery/t/055_standby_snapshot_export.pl
+++ b/src/test/recovery/t/055_standby_snapshot_export.pl
@@ -122,7 +122,6 @@ $s1->query_safe('COMMIT');
 $u->query_safe('COMMIT');
 $primary->safe_psql('postgres',
 	q[INSERT INTO victim VALUES (7, repeat('y', 1200))]);
-$o->query_safe('COMMIT');
 $primary->wait_for_replay_catchup($standby);
 
 # Sessions that never touched the exported snapshot must agree with the
@@ -151,6 +150,13 @@ $s3->query_safe('BEGIN ISOLATION LEVEL REPEATABLE READ');
 my $snap2 = $s3->query_safe('SELECT pg_export_snapshot()');
 my $before = $s3->query_safe('SELECT count(*) FROM victim');
 
+my $file2 = slurp_file($standby->data_dir . "/pg_snapshots/$snap2");
+my ($sof2) = $file2 =~ /^sof:(\d+)$/m;
+note("BDT snapshot saved for post-promotion re-export $snap2: sof=$sof2");
+
+$o->query_safe('COMMIT');
+$primary->wait_for_replay_catchup($standby);
+
 $standby->promote;
 $standby->poll_query_until('postgres', 'SELECT NOT pg_is_in_recovery()')
   or die "standby never finished promotion";
@@ -172,6 +178,16 @@ $s4->query_safe('RELEASE sp');
 my $snap3 = $s4->query_safe('SELECT pg_export_snapshot()');
 
 my $file3 = slurp_file($standby->data_dir . "/pg_snapshots/$snap3");
+my ($sof3) = $file3 =~ /^sof:(\d+)$/m;
+my ($xmax3) = $file3 =~ /^xmax:(\d+)$/m;
+my @subxids3 = $file3 =~ /^sxp:(\d+)$/mg;
+my @post_xmax_subxids3 = grep { $_ >= $xmax3 } @subxids3;
+note(
+	"BDT re-exported snapshot $snap3: sof=$sof3; xmax=$xmax3; sxp=["
+	  . join(', ', @subxids3)
+	  . "]; sxp >= xmax=["
+	  . join(', ', @post_xmax_subxids3)
+	  . "]");
 like($file3, qr/^sxcnt:[1-9]/m,
 	'a recovery-taken snapshot re-exports its subxip array after a write');