diff --git a/src/pyside6/gui_pyside6.py b/src/pyside6/gui_pyside6.py
index 326376f..a09881f 100644
--- a/src/pyside6/gui_pyside6.py
+++ b/src/pyside6/gui_pyside6.py
@@ -30,8 +30,8 @@ class MainWindow(QMainWindow):
                 self.trades[unique_item].add_trade(message)
             else:
                 collection = TradeCollection(message, self)
-                index = self.main_widget.addTab(collection, message.trade.item)
-                collection.index = index
+                collection.setParent(self.main_widget)
+                self.main_widget.addTab(collection, message.trade.item)
                 self.trades[message.trade.unique_item()] = collection
                 self.show()