diff --git a/SDT/schema4.0/test/productClass-test.xml b/SDT/schema4.0/test/productClass-test.xml
index 23d2662967106a5a3eb4ad61f77698af78d9ee9d..52b5a6660f7450bbff36a0e04c823ea1ecb4d868 100644
--- a/SDT/schema4.0/test/productClass-test.xml
+++ b/SDT/schema4.0/test/productClass-test.xml
@@ -27,10 +27,6 @@
 			</DeviceClass>
 		</ProductClass>
 
-<!--	TODO: test <extends> element, but only when DeviceClas is optional
- 		<Product id="AnotherTestProduct">
-		</Product> -->
-
 		<!-- Derived ProductClass -->
 
 		<ProductClass id="DerivedProductClass" semanticURI="http://example.com/DerivedProduct.rdf">