diff --git a/src/ifcopenshell-python/test/util/test_unit.py b/src/ifcopenshell-python/test/util/test_unit.py
index e0d304888b..6e28a28e70 100644
--- a/src/ifcopenshell-python/test/util/test_unit.py
+++ b/src/ifcopenshell-python/test/util/test_unit.py
@@ -241,6 +241,8 @@ class TestConvertFileLengthUnits(test.bootstrap.IFC2X3):
         unit = ifcopenshell.api.unit.add_si_unit(self.file, unit_type="LENGTHUNIT", prefix="MILLI")
         ifcopenshell.api.unit.assign_unit(self.file, units=[unit])
         output = subject.convert_file_length_units(self.file, target_units="METER")
+        # there was some renumbering bug in the rocksdb rewrite this statement is to test for that
+        assert max(i.id() for i in output) == len(output.wrapped_data.entity_names()) + 1
         assert subject.get_full_unit_name(subject.get_project_unit(output, "LENGTHUNIT")) == "METRE"
 
     def test_attribute_conversion(self):