diff --git a/docs/en/sql-reference/statements/alter/partition.md b/docs/en/sql-reference/statements/alter/partition.md
index 2a65bc83824..922952f0e8b 100644
--- a/docs/en/sql-reference/statements/alter/partition.md
+++ b/docs/en/sql-reference/statements/alter/partition.md
@@ -286,7 +286,7 @@ ALTER TABLE mt DELETE IN PARTITION 2 WHERE p = 2;
 You can specify the partition expression in `ALTER ... PARTITION` queries in different ways:
 
 -   As a value from the `partition` column of the `system.parts` table. For example, `ALTER TABLE visits DETACH PARTITION 201901`.
--   As the expression from the table column. Constants and constant expressions are supported. The expression must be wrapped in a `tuple()` function. For example, `ALTER TABLE visits DETACH PARTITION tuple(toYYYYMM(toDate('2019-01-25')))`.
+-   As the expression tuple that matches (in types) a table partitioning keys tuple. In the case of a single element partitioning key, you should wrap it in the `tuple (...)` function. For example, `ALTER TABLE visits DETACH PARTITION tuple(toYYYYMM(toDate('2019-01-25')))`.
 -   Using the partition ID. Partition ID is a string identifier of the partition (human-readable, if possible) that is used as the names of partitions in the file system and in ZooKeeper. The partition ID must be specified in the `PARTITION ID` clause, in a single quotes. For example, `ALTER TABLE visits DETACH PARTITION ID '201901'`.
 -   In the [ALTER ATTACH PART](#alter_attach-partition) and [DROP DETACHED PART](#alter_drop-detached) query, to specify the name of a part, use string literal with a value from the `name` column of the [system.detached_parts](../../../operations/system-tables/detached_parts.md#system_tables-detached_parts) table. For example, `ALTER TABLE visits ATTACH PART '201901_1_1_0'`.