diff --git a/src/ifcopenshell-python/test/fixtures/validate/fail-derived-as-nil.ifc b/src/ifcopenshell-python/test/fixtures/validate/fail-derived-as-nil.ifc
new file mode 100644
index 0000000000..5638fb5b4c
--- /dev/null
+++ b/src/ifcopenshell-python/test/fixtures/validate/fail-derived-as-nil.ifc
@@ -0,0 +1,10 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [CoordinationView]'),'2;1');
+FILE_NAME('','2022-11-23T13:41:45',(),(),'IfcOpenShell 0.7.0','IfcOpenShell 0.7.0','');
+FILE_SCHEMA(('IFC4'));
+ENDSEC;
+DATA;
+#1=IFCSIUNIT(*,.LENGTHUNIT.,*,.METRE.);
+ENDSEC;
+END-ISO-10303-21;
diff --git a/src/ifcopenshell-python/test/fixtures/validate/fail-nil-as-derived.ifc b/src/ifcopenshell-python/test/fixtures/validate/fail-nil-as-derived.ifc
new file mode 100644
index 0000000000..5638fb5b4c
--- /dev/null
+++ b/src/ifcopenshell-python/test/fixtures/validate/fail-nil-as-derived.ifc
@@ -0,0 +1,10 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [CoordinationView]'),'2;1');
+FILE_NAME('','2022-11-23T13:41:45',(),(),'IfcOpenShell 0.7.0','IfcOpenShell 0.7.0','');
+FILE_SCHEMA(('IFC4'));
+ENDSEC;
+DATA;
+#1=IFCSIUNIT(*,.LENGTHUNIT.,*,.METRE.);
+ENDSEC;
+END-ISO-10303-21;
diff --git a/src/ifcopenshell-python/test/fixtures/validate/pass-derived-ok.ifc b/src/ifcopenshell-python/test/fixtures/validate/pass-derived-ok.ifc
new file mode 100644
index 0000000000..a8372bab1e
--- /dev/null
+++ b/src/ifcopenshell-python/test/fixtures/validate/pass-derived-ok.ifc
@@ -0,0 +1,10 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [CoordinationView]'),'2;1');
+FILE_NAME('','2022-11-23T13:41:45',(),(),'IfcOpenShell 0.7.0','IfcOpenShell 0.7.0','');
+FILE_SCHEMA(('IFC4'));
+ENDSEC;
+DATA;
+#1=IFCSIUNIT(*,.LENGTHUNIT.,$,.METRE.);
+ENDSEC;
+END-ISO-10303-21;