diff --git a/tidb-lightning/tidb-lightning-configuration.md b/tidb-lightning/tidb-lightning-configuration.md
index d89a335118b69..1c9e5a85bd1e7 100644
--- a/tidb-lightning/tidb-lightning-configuration.md
+++ b/tidb-lightning/tidb-lightning-configuration.md
@@ -358,10 +358,6 @@ distsql-scan-concurrency = 15
 index-serial-scan-concurrency = 20
 checksum-table-concurrency = 2
 
-# Sets other TiDB session variables
-# [tidb.session-vars]
-# tidb_enable_clustered_index = "OFF"
-
 # The default SQL mode used to parse and execute the SQL statements.
 sql-mode = "ONLY_FULL_GROUP_BY,NO_AUTO_CREATE_USER"
 # Sets maximum packet size allowed for SQL connections.