diff --git a/src/blenderbim/blenderbim/bim/prop.py b/src/blenderbim/blenderbim/bim/prop.py
index 182bf63da4..13b7f82078 100644
--- a/src/blenderbim/blenderbim/bim/prop.py
+++ b/src/blenderbim/blenderbim/bim/prop.py
@@ -442,9 +442,6 @@ class BIMObjectProperties(PropertyGroup):
 
 
 class BIMMaterialProperties(PropertyGroup):
-    is_external: BoolProperty(name="Has External Definition")
-    name: StringProperty(name="Name")
-    attributes: CollectionProperty(name="Attributes", type=Attribute)
     # In Blender, a material object can map to an IFC material, IFC surface style, or both
     ifc_style_id: IntProperty(name="IFC Style ID")
     shading_checksum: StringProperty(name="Shading Checksum")