diff --git a/cura/Machines/ContainerNode.py b/cura/Machines/ContainerNode.py
index 32ebe203a3..74d08dff6c 100644
--- a/cura/Machines/ContainerNode.py
+++ b/cura/Machines/ContainerNode.py
@@ -24,6 +24,7 @@ class ContainerNode:
         self.children_map = {}  # type: Dict[str, ContainerNode]  # Mapping from container ID to container node.
 
     ##  Gets the metadata of the container that this node represents.
+    #   Getting the metadata from the container directly is about 10x as fast.
     #   \return The metadata of the container in this node.
     @deprecated("Get the metadata from the container with the ID of this node yourself.", "4.3")
     def getMetadata(self):
diff --git a/cura/Machines/MaterialManager.py b/cura/Machines/MaterialManager.py
index 4790314b25..72862d43f0 100644
--- a/cura/Machines/MaterialManager.py
+++ b/cura/Machines/MaterialManager.py
@@ -1,6 +1,5 @@
 # Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
-
 from collections import defaultdict
 import copy
 import uuid
@@ -109,10 +108,10 @@ class MaterialManager(QObject):
             nozzle_name = extruder_stack.variant.getName()
 
         # Fetch the available materials (ContainerNode) for the current active machine and extruder setup.
-        materials =self.getAvailableMaterials(machine.definition.getId(), nozzle_name)
+        materials = self.getAvailableMaterials(machine.definition.getId(), nozzle_name)
         compatible_material_diameter = str(round(extruder_stack.getCompatibleMaterialDiameter()))
-
-        return {key: material for key, material in materials.items() if material.getMetaDataEntry("approximate_diameter") == compatible_material_diameter}
+        result = {key: material for key, material in materials.items() if material.container.getMetaDataEntry("approximate_diameter") == compatible_material_diameter}
+        return result
 
     #
     # Gets MaterialNode for the given extruder and machine with the given material name.