diff --git a/cura/Machines/Models/QualityManagementModel.py b/cura/Machines/Models/QualityManagementModel.py
index 19885cddc9..ffdb022f38 100644
--- a/cura/Machines/Models/QualityManagementModel.py
+++ b/cura/Machines/Models/QualityManagementModel.py
@@ -119,7 +119,7 @@ class QualityManagementModel(ListModel):
             new_quality_changes = self._createQualityChanges(quality_group.quality_type, None, new_name, global_stack, extruder_stack = None)
             container_registry.addContainer(new_quality_changes)
         else:
-            for metadata in [quality_changes_group.metadata_for_global] + quality_changes_group.metadata_per_extruder.values():
+            for metadata in [quality_changes_group.metadata_for_global] + list(quality_changes_group.metadata_per_extruder.values()):
                 containers = container_registry.findContainers(id = metadata["id"])
                 if not containers:
                     continue