diff --git a/cura/PrintInformation.py b/cura/PrintInformation.py
index 279e7e0c03..50d80e11bb 100644
--- a/cura/PrintInformation.py
+++ b/cura/PrintInformation.py
@@ -212,14 +212,13 @@ class PrintInformation(QObject):
         material_preference_values = json.loads(Preferences.getInstance().getValue("cura/material_settings"))
 
         extruder_stacks = global_stack.extruders
-        for extruder_key in global_stack.extruders.keys():
-            index = int(extruder_key)
+        for position, extruder_stack in extruder_stacks.keys():
+            index = int(position)
             if index >= len(self._material_amounts):  # Right now the _material_amounts is a list, where the index is the extruder number
                 continue
             amount = self._material_amounts[index]
             ## Find the right extruder stack. As the list isn't sorted because it's a annoying generator, we do some
             #  list comprehension filtering to solve this for us.
-            extruder_stack = extruder_stacks[str(index)]
             density = extruder_stack.getMetaDataEntry("properties", {}).get("density", 0)
             material = extruder_stack.findContainer({"type": "material"})