diff --git a/ydb/library/yql/core/type_ann/type_ann_pg.cpp b/ydb/library/yql/core/type_ann/type_ann_pg.cpp
index 56237c8abcd7..04e6d45bce42 100644
--- a/ydb/library/yql/core/type_ann/type_ann_pg.cpp
+++ b/ydb/library/yql/core/type_ann/type_ann_pg.cpp
@@ -1823,7 +1823,7 @@ bool ScanColumns(TExprNode::TPtr root, TInputs& inputs, const THashSet<TString>&
                             }
                         }
 
-                        if (x.Order && x.Order->IsDuplicated(TString(node->Tail().Content()))) {
+                        if (x.Order && x.Order->IsDuplicatedIgnoreCase(TString(node->Tail().Content()))) {
                             ctx.Expr.AddError(TIssue(ctx.Expr.GetPosition(node->Pos()),
                                     TStringBuilder() << "Column reference is ambiguous: " << node->Tail().Content()));
                                 isError = true;
diff --git a/ydb/library/yql/core/ut/yql_column_order_ut.cpp b/ydb/library/yql/core/ut/yql_column_order_ut.cpp
index 9af0fb4f6989..38e012b5dfda 100644
--- a/ydb/library/yql/core/ut/yql_column_order_ut.cpp
+++ b/ydb/library/yql/core/ut/yql_column_order_ut.cpp
@@ -32,6 +32,13 @@ Y_UNIT_TEST_SUITE(TYqlColumnOrder) {
         UNIT_ASSERT_EQUAL(order.AddColumn("a_generated_2_generated_2"), "a_generated_2_generated_2_generated_2");
     }
 
+    Y_UNIT_TEST(ColumnOrderCaseSensetive) {
+        TColumnOrder order;
+        UNIT_ASSERT_EQUAL(order.AddColumn("a"), "a");
+        UNIT_ASSERT_EQUAL(order.AddColumn("A"), "A");
+        UNIT_ASSERT_EQUAL(order.IsDuplicatedIgnoreCase("a"), true);
+    }
+
     Y_UNIT_TEST(ColumnOrderGeneratedMatchOverVectorCtor) {
         TColumnOrder order(TVector<TString>{"a", "a", "a_generated_2", "a_generated_2_generated_2"});
         TVector<TColumnOrder::TOrderedItem> got(order.begin(), order.end());
diff --git a/ydb/library/yql/core/yql_type_annotation.cpp b/ydb/library/yql/core/yql_type_annotation.cpp
index 05c7403fe0bf..92eed308c1b2 100644
--- a/ydb/library/yql/core/yql_type_annotation.cpp
+++ b/ydb/library/yql/core/yql_type_annotation.cpp
@@ -150,7 +150,7 @@ TString TColumnOrder::AddColumn(const TString& name) {
     return name;
 }
 
-bool TColumnOrder::IsDuplicated(const TString& name) const {
+bool TColumnOrder::IsDuplicatedIgnoreCase(const TString& name) const {
     auto it = UseCountLcase_.find(to_lower(name));
     return it != UseCount_.end() && it->second > 1;
 }
diff --git a/ydb/library/yql/core/yql_type_annotation.h b/ydb/library/yql/core/yql_type_annotation.h
index e94a2385d7a5..2c4c32aa9122 100644
--- a/ydb/library/yql/core/yql_type_annotation.h
+++ b/ydb/library/yql/core/yql_type_annotation.h
@@ -170,7 +170,7 @@ class TColumnOrder {
     explicit TColumnOrder(const TVector<TString>& order);
     TString AddColumn(const TString& name);
 
-    bool IsDuplicated(const TString& name) const;
+    bool IsDuplicatedIgnoreCase(const TString& name) const;
 
     void Shrink(size_t remain);