diff --git a/components/tachart/tasources.pas b/components/tachart/tasources.pas
index 7f5fb9084f..f7eadf0e90 100644
--- a/components/tachart/tasources.pas
+++ b/components/tachart/tasources.pas
@@ -1082,14 +1082,24 @@ begin
 end;
 
 procedure TCalculatedChartSource.ExtractItem(AIndex: Integer);
+
+  function YByOrder(AOrderIndex: Integer): Double;
+  begin
+    if AOrderIndex = 0 then
+      Result := FItem.Y
+    else
+      Result := FItem.YList[AOrderIndex - 1];
+  end;
+
 var
   t: TDoubleDynArray;
   i: Integer;
 begin
   FItem := Origin[AIndex]^;
-  SetLength(t, Length(FYOrder));
-  for i := 0 to High(FYOrder) do
-    t[i] := FItem.YList[FYOrder[i]];
+  SetLength(t, High(FYOrder));
+  for i := 1 to High(FYOrder) do
+    t[i - 1] := YByOrder(FYOrder[i]);
+  FItem.Y := YByOrder(FYOrder[0]);
   FItem.YList := t;
 end;
 
@@ -1211,8 +1221,7 @@ begin
 
   FOriginYCount := FOrigin.YCount;
   if ReorderYList = '' then begin
-    FYCount := FOrigin.YCount;
-    SetLength(FYOrder,  Max(FYCount - 1, 0));
+    SetLength(FYOrder,  FOriginYCount);
     for i := 0 to High(FYOrder) do
       FYOrder[i] := i;
   end
@@ -1222,15 +1231,14 @@ begin
       order.CommaText := ReorderYList;
       SetLength(FYOrder, order.Count);
       for i := 0 to High(FYOrder) do
-        FYOrder[i] :=
-          EnsureRange(StrToIntDef(order[i], 0), 0, FOrigin.YCount - 2);
-      FYCount := Length(FYOrder) + 1;
+        FYOrder[i] := EnsureRange(StrToIntDef(order[i], 0), 0, FOriginYCount - 1);
     finally
       order.Free;
     end;
   end;
+  FYCount := Length(FYOrder);
 
-  SetLength(FItem.YList, Length(FYOrder));
+  SetLength(FItem.YList, Max(High(FYOrder), 0));
   Changed(nil);
 end;
 
diff --git a/components/tachart/test/SourcesTest.pas b/components/tachart/test/SourcesTest.pas
index 3b91e9e91b..4e522bc8a7 100644
--- a/components/tachart/test/SourcesTest.pas
+++ b/components/tachart/test/SourcesTest.pas
@@ -200,23 +200,27 @@ end;
 
 procedure TCalculatedSourceTest.Reorder;
 var
-  i, j: Integer;
+  i: Integer;
 begin
   AssertEquals(3, FSource.YCount);
   FSource.ReorderYList := '2';
+  AssertEquals(1, FSource.YCount);
+  AssertEquals(104, FSource[0]^.Y);
+  AssertEquals(204, FSource[1]^.Y);
+  FSource.ReorderYList := '0,2';
   AssertEquals(2, FSource.YCount);
+  AssertEquals(102, FSource[0]^.Y);
   AssertEquals(104, FSource[0]^.YList[0]);
+  AssertEquals(202, FSource[1]^.Y);
   AssertEquals(204, FSource[1]^.YList[0]);
-  FSource.ReorderYList := '0,0,0';
-  AssertEquals(4, FSource.YCount);
-  AssertEquals(103, FSource[0]^.YList[0]);
-  AssertEquals(103, FSource[0]^.YList[1]);
-  AssertEquals(103, FSource[0]^.YList[2]);
+  FSource.ReorderYList := '1,1,1';
+  AssertEquals(3, FSource.YCount);
+  AssertEquals(103, FSource[0]^.Y);
+  AssertEquals([103, 103], FSource[0]^.YList);
   FSource.ReorderYList := '';
   for i := 0 to FSource.Count - 1 do begin
     AssertEquals(FOrigin[i]^.Y, FSource[i]^.Y);
-    for j := 0 to FSource.YCount - 2 do
-      AssertEquals(FOrigin[i]^.YList[j], FSource[i]^.YList[j]);
+    AssertEquals(FOrigin[i]^.YList, FSource[i]^.YList);
   end;
 end;