diff --git a/cura/Machines/MaterialNode.py b/cura/Machines/MaterialNode.py
index 7d71b24939..2ea0cd12b5 100644
--- a/cura/Machines/MaterialNode.py
+++ b/cura/Machines/MaterialNode.py
@@ -18,7 +18,7 @@ if TYPE_CHECKING:
 #
 #   Its subcontainers are quality profiles.
 class MaterialNode(ContainerNode):
-    def __init__(self, container_id, variant: "VariantNode") -> None:
+    def __init__(self, container_id: str, variant: "VariantNode") -> None:
         super().__init__(container_id)
         self.variant = variant
         self.qualities = {}  # type: Dict[str, QualityNode] # Mapping container IDs to quality profiles.
@@ -29,10 +29,6 @@ class MaterialNode(ContainerNode):
         self.base_file = my_metadata["base_file"]
         self.material_type = my_metadata["material"]
         self.guid = my_metadata["GUID"]
-        # MaterialNode can represent an empty_material container, which has no diameter.
-        self.diameter = None  # type: Optional[str]
-        if "properties" in my_metadata:
-            self.diameter = my_metadata["properties"]["diameter"]
         self._loadAll()
         container_registry.containerRemoved.connect(self._onRemoved)
         container_registry.containerMetaDataChanged.connect(self._onMetadataChanged)
@@ -133,8 +129,6 @@ class MaterialNode(ContainerNode):
         self.material_type = new_metadata["material"]
         old_guid = self.guid
         self.guid = new_metadata["GUID"]
-        if "properties" in new_metadata:
-            self.diameter = new_metadata["properties"]["diameter"]
         if self.base_file != old_base_file or self.material_type != old_material_type or self.guid != old_guid:  # List of quality profiles could've changed.
             self.qualities = {}
             self._loadAll()  # Re-load the quality profiles for this node.
diff --git a/cura/Settings/MachineManager.py b/cura/Settings/MachineManager.py
index 5f4a5a2f9c..ce8ea8b85e 100755
--- a/cura/Settings/MachineManager.py
+++ b/cura/Settings/MachineManager.py
@@ -1354,7 +1354,8 @@ class MachineManager(QObject):
             old_approximate_material_diameter = None  # type: Optional[float]
             if candidate_materials:
                 candidate_material = list(candidate_materials.values())[0]
-                old_approximate_material_diameter = int(round(float(candidate_material.diameter)))
+                default_material_diameter = "2.85"
+                old_approximate_material_diameter = int(round(float(candidate_material.container.getMetaDataEntry("properties/diameter", default_material_diameter))))
             new_approximate_material_diameter = int(self._global_container_stack.extruderList[int(position_item)].getApproximateMaterialDiameter())
 
             # Only switch to the old candidate material if the approximate material diameter of the extruder stays the