diff --git a/src/substrait/textplan/converter/InitialPlanProtoVisitor.cpp b/src/substrait/textplan/converter/InitialPlanProtoVisitor.cpp
index 4a69e5b3..17e6f1ce 100644
--- a/src/substrait/textplan/converter/InitialPlanProtoVisitor.cpp
+++ b/src/substrait/textplan/converter/InitialPlanProtoVisitor.cpp
@@ -466,9 +466,9 @@ void InitialPlanProtoVisitor::updateLocalSchema(
               }
             }
             if (field->alias.empty()) {
-              size_t fieldRefNum = relationData->generatedFieldReferences.size() - 1;
-              relationData->seenFieldReferenceNames.insert(
-                  std::make_tuple(field->name, fieldRefNum));
+              relationData->seenFieldReferenceNames.insert(std::make_pair(
+                  field->name,
+                  relationData->generatedFieldReferences.size() - 1));
             }
           } else {
             ::substrait::proto::Rel sanitizedRelation = *currentRelationScope_;