diff --git a/src/ifcopenshell-python/ifcopenshell/api/cost/assign_cost_item_quantity.py b/src/ifcopenshell-python/ifcopenshell/api/cost/assign_cost_item_quantity.py
index 542347fa11..8ca6bf8559 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/cost/assign_cost_item_quantity.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/cost/assign_cost_item_quantity.py
@@ -104,7 +104,7 @@ class Usecase:
         if self.settings["prop_name"]:
             self.quantities = set(self.settings["cost_item"].CostQuantities or [])
         for product in self.settings["products"]:
-            if not product.is_a("IfcElement"):
+            if product.is_a("IfcSpatialElement"):
                 continue
             self.assign_cost_control(related_object=product, cost_item=self.settings["cost_item"])
             if self.settings["prop_name"]: