diff --git a/qt_ui/windows/mission/QPackageDialog.py b/qt_ui/windows/mission/QPackageDialog.py
index f83bf6d9..6ef908bb 100644
--- a/qt_ui/windows/mission/QPackageDialog.py
+++ b/qt_ui/windows/mission/QPackageDialog.py
@@ -314,7 +314,7 @@ class QNewPackageDialog(QPackageDialog):
 
     def on_cancel(self) -> None:
         super().on_cancel()
-        for flight in self.package_model.package.flights:
+        for flight in list(self.package_model.package.flights):
             self.package_model.cancel_or_abort_flight(flight)