diff --git a/tests/queries/0_stateless/01506_buffer_table_alter_block_structure_2.sql b/tests/queries/0_stateless/01506_buffer_table_alter_block_structure_2.sql
index 8862037c82bf..f9c227942ac0 100644
--- a/tests/queries/0_stateless/01506_buffer_table_alter_block_structure_2.sql
+++ b/tests/queries/0_stateless/01506_buffer_table_alter_block_structure_2.sql
@@ -5,12 +5,11 @@ CREATE TABLE buf_dest (timestamp DateTime)
 ENGINE = MergeTree PARTITION BY toYYYYMMDD(timestamp)
 ORDER BY (timestamp);
 
-CREATE TABLE buf (timestamp DateTime) Engine = Buffer(currentDatabase(), buf_dest, 16, 0.1, 0.1, 2000000, 20000000, 100000000, 300000000);;
+CREATE TABLE buf (timestamp DateTime) Engine = Buffer(currentDatabase(), buf_dest, 16, 86400, 86400, 2000000, 20000000, 100000000, 300000000);;
 
 INSERT INTO buf (timestamp) VALUES (toDateTime('2020-01-01 00:05:00'));
 
---- wait for buffer to flush
-SELECT sleep(1) from numbers(1) settings max_block_size=1 format Null;
+OPTIMIZE TABLE buf;
 
 ALTER TABLE buf_dest ADD COLUMN s String;
 ALTER TABLE buf ADD COLUMN s String;