diff --git a/components/tachart/tasources.pas b/components/tachart/tasources.pas
index faf123f4cb..1b1ea160ed 100644
--- a/components/tachart/tasources.pas
+++ b/components/tachart/tasources.pas
@@ -854,28 +854,9 @@ begin
     end;
 end;
 
-function CompareDataItemY(AItem1, AItem2: Pointer): Integer;
-var
-  i: Integer;
-  item1: PChartDataItem absolute AItem1;
-  item2: PChartDataItem absolute AItem2;
-begin
-  Result := CompareFloat(item1^.Y, item2^.Y);
-  if Result = 0 then
-    for i := 0 to Min(High(item1^.YList), High(item2^.YList)) do begin
-      Result := CompareFloat(item1^.YList[i], item2^.YList[i]);
-      if Result <> 0 then
-        exit;
-    end;
-end;
-
 procedure TListChartSource.Sort;
 begin
-  if XCount > 0 then
-    FData.Sort(@CompareDataItemX)
-  else
-  if YCount > 0 then
-    FData.Sort(@CompareDataItemY);
+  FData.Sort(@CompareDataItemX);
 end;
 
 procedure TListChartSource.UpdateCachesAfterAdd(AX, AY: Double);