diff --git a/system-variables.md b/system-variables.md
index 27d4fec816dbc..86a806534d7f1 100644
--- a/system-variables.md
+++ b/system-variables.md
@@ -4104,6 +4104,24 @@ mysql> desc select count(distinct a) from test.t;
- Default value: `OFF`
- This variable controls whether to enable the [Cross-database binding](/sql-plan-management.md#cross-database-binding) feature.
+### tidb_opt_enable_no_decorrelate_in_select New in v8.5.4
+
+- Scope: SESSION | GLOBAL
+- Persists to cluster: Yes
+- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): Yes
+- Type: Boolean
+- Default value: `OFF`
+- This variable controls whether to apply the hint [`NO_DECORRELATE`](/optimizer-hints.md#no_decorrelate) at the session/global level for all queries with a subquery in the select list.
+
+### tidb_opt_enable_semi_join_rewrite New in v8.5.4
+
+- Scope: SESSION | GLOBAL
+- Persists to cluster: Yes
+- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No
+- Type: Boolean
+- Default value: `OFF`
+- This variable controls whether to apply the hint [`SEMI_JOIN_REWRITE`](/optimizer-hints.md#semi_join_rewrite) at the session/global level for all queries that contain subqueries.
+
### tidb_opt_fix_control New in v6.5.3 and v7.1.0