diff --git a/src/frontend/src/optimizer/rule/pull_up_correlated_predicate_agg_rule.rs b/src/frontend/src/optimizer/rule/pull_up_correlated_predicate_agg_rule.rs
index 84ee726e36f7..7823c7f41f7b 100644
--- a/src/frontend/src/optimizer/rule/pull_up_correlated_predicate_agg_rule.rs
+++ b/src/frontend/src/optimizer/rule/pull_up_correlated_predicate_agg_rule.rs
@@ -32,6 +32,8 @@ use crate::utils::{Condition, IndexSet};
 /// Before:
 ///
 /// ```text
+///        Filter
+///          |
 ///     LogicalApply
 ///    /            \
 ///  LHS          Project
@@ -46,6 +48,8 @@ use crate::utils::{Condition, IndexSet};
 /// After:
 ///
 /// ```text
+///        Filter
+///          |
 ///     LogicalJoin [yyy = xxx]
 ///    /            \
 ///  LHS          Project