diff --git a/cura/Machines/Models/BaseMaterialsModel.py b/cura/Machines/Models/BaseMaterialsModel.py
index c7dbadf54a..edcdacb8a1 100644
--- a/cura/Machines/Models/BaseMaterialsModel.py
+++ b/cura/Machines/Models/BaseMaterialsModel.py
@@ -141,7 +141,7 @@ class BaseMaterialsModel(ListModel):
         nozzle_name = extruder_stack.variant.getName()
         materials = ContainerTree.getInstance().machines[global_stack.definition.getId()].variants[nozzle_name].materials
         approximate_material_diameter = extruder_stack.getApproximateMaterialDiameter()
-        self._available_materials = {key: material for key, material in materials.items() if float(material.container.getMetaDataEntry("approximate_diameter")) == approximate_material_diameter}
+        self._available_materials = {key: material for key, material in materials.items() if float(material.container.getMetaDataEntry("approximate_diameter", -1)) == approximate_material_diameter}
 
     ## This method is used by all material models in the beginning of the
     #  _update() method in order to prevent errors. It's the same in all models