diff --git a/src/batch/benches/hash_agg.rs b/src/batch/benches/hash_agg.rs
index 1d77a3430c2a6..b4d773ae425f2 100644
--- a/src/batch/benches/hash_agg.rs
+++ b/src/batch/benches/hash_agg.rs
@@ -39,7 +39,7 @@ fn create_agg_call(
     return_type: DataType,
 ) -> PbAggCall {
     PbAggCall {
-        kind: agg_type.to_protobuf() as i32,
+        kind: agg_type.to_protobuf_simple() as i32,
         args: args
             .into_iter()
             .map(|col_idx| PbInputRef {
diff --git a/src/expr/core/src/aggregate/def.rs b/src/expr/core/src/aggregate/def.rs
index 8a6ba3ead6fb9..3abe80dcd4d31 100644
--- a/src/expr/core/src/aggregate/def.rs
+++ b/src/expr/core/src/aggregate/def.rs
@@ -279,7 +279,7 @@ impl AggType {
         }
     }
 
-    pub fn to_protobuf(&self) -> PbAggKind {
+    pub fn to_protobuf_simple(&self) -> PbAggKind {
         match self {
             Self::Builtin(pb) => *pb,
             Self::UserDefined(_) => PbAggKind::UserDefined,
diff --git a/src/frontend/src/optimizer/plan_node/generic/over_window.rs b/src/frontend/src/optimizer/plan_node/generic/over_window.rs
index c8d2f64ba6141..5622d1e8952cf 100644
--- a/src/frontend/src/optimizer/plan_node/generic/over_window.rs
+++ b/src/frontend/src/optimizer/plan_node/generic/over_window.rs
@@ -121,7 +121,7 @@ impl PlanWindowFunction {
             DenseRank => PbType::General(PbGeneralType::DenseRank as _),
             Lag => PbType::General(PbGeneralType::Lag as _),
             Lead => PbType::General(PbGeneralType::Lead as _),
-            Aggregate(agg_type) => PbType::Aggregate(agg_type.to_protobuf() as _),
+            Aggregate(agg_type) => PbType::Aggregate(agg_type.to_protobuf_simple() as _),
         };
 
         PbWindowFunction {