diff --git a/src/test/recovery/t/018_wal_optimize.pl b/src/test/recovery/t/018_wal_optimize.pl
index 95063ab..5d476a4 100644
--- a/src/test/recovery/t/018_wal_optimize.pl
+++ b/src/test/recovery/t/018_wal_optimize.pl
@@ -11,7 +11,7 @@ use warnings;
 
 use PostgresNode;
 use TestLib;
-use Test::More tests => 28;
+use Test::More tests => 32;
 
 sub check_orphan_relfilenodes
 {
@@ -43,6 +43,8 @@ sub run_wal_optimize
 	$node->append_conf('postgresql.conf', qq(
 wal_level = $wal_level
 max_prepared_transactions = 1
+wal_log_hints = on
+effective_io_block_size = 0
 ));
 	$node->start;
 
@@ -194,6 +196,24 @@ max_prepared_transactions = 1
 	is($result, qq(3),
 	   "wal_level = $wal_level, SET TABLESPACE in subtransaction");
 
+	$node->safe_psql('postgres', "
+		BEGIN;
+		CREATE TABLE test3a5 (c int PRIMARY KEY);
+		SAVEPOINT q; INSERT INTO test3a5 VALUES (1); ROLLBACK TO q;
+		CHECKPOINT;
+		INSERT INTO test3a5 VALUES (1);  -- set index hint bit
+		INSERT INTO test3a5 VALUES (2);
+		COMMIT;");
+	$node->stop('immediate');
+	$node->start;
+	$result = $node->psql('postgres', );
+	my($ret, $stdout, $stderr) = $node->psql(
+		'postgres', "INSERT INTO test3a5 VALUES (2);");
+	is($ret, qq(3),
+	   "wal_level = $wal_level, unique index LP_DEAD");
+	like($stderr, qr/violates unique/,
+	   "wal_level = $wal_level, unique index LP_DEAD message");
+
 	# UPDATE touches two buffers; one is BufferNeedsWAL(); the other is not.
 	$node->safe_psql('postgres', "
 		BEGIN;