diff --git a/src/blenderbim/test/bim/bootstrap.py b/src/blenderbim/test/bim/bootstrap.py
index 74f464bc44..eb86eac57c 100644
--- a/src/blenderbim/test/bim/bootstrap.py
+++ b/src/blenderbim/test/bim/bootstrap.py
@@ -269,7 +269,14 @@ def the_void_name_is_filled_by_filling(name, filling):
     element = ifc.by_id(the_object_name_exists(name).BIMObjectProperties.ifc_definition_id)
     if any(rel.RelatedBuildingElement.Name == filling for rel in element.HasFillings):
         return True
-    assert False, f"Filling was not found"
+    assert False, f"No filling found"
+
+
+def the_void_name_is_not_filled_by_filling(name, filling):
+    ifc = IfcStore.get_file()
+    element = ifc.by_id(the_object_name_exists(name).BIMObjectProperties.ifc_definition_id)
+    if any(rel.RelatedBuildingElement.Name == filling for rel in element.HasFillings):
+        assert False, f"A filling was found"
 
 
 def the_object_name_should_display_as_mode(name, mode):
@@ -325,7 +332,8 @@ definitions = {
     'the object "(.*)" should display as "(.*)"': the_object_name_should_display_as_mode,
     'the object "(.*)" has "([0-9]+)" vertices': the_object_name_has_number_vertices,
     'the object "(.*)" is at "(.*)"': the_object_name_is_at_location,
-    'the object "(.*)" is filled by "(.*)"': the_void_name_is_filled_by_filling,
+    'the void "(.*)" is filled by "(.*)"': the_void_name_is_filled_by_filling,
+    'the void "(.*)" is not filled by "(.*)"': the_void_name_is_not_filled_by_filling,
 }