diff --git a/src/bonsai/bonsai/tool/material.py b/src/bonsai/bonsai/tool/material.py
index 695759227c..308658737f 100644
--- a/src/bonsai/bonsai/tool/material.py
+++ b/src/bonsai/bonsai/tool/material.py
@@ -331,6 +331,10 @@ class Material(bonsai.core.tool.Material):
 
     @classmethod
     def get_style(cls, material: ifcopenshell.entity_instance) -> Union[ifcopenshell.entity_instance, None]:
+        if not material.is_a("IfcMaterial"):
+            # material may also be an IfcMaterialConstituentSet / IfcMaterialLayerSet /
+            # IfcMaterialProfileSet / IfcMaterialList, none of which have HasRepresentation.
+            return None
         for material_representation in material.HasRepresentation:
             for representation in material_representation.Representations:
                 for item in representation.Items: