diff --git a/time/rdf/time-prov.ttl b/time/rdf/time-prov.ttl
index f2ef08c5..538cbde6 100644
--- a/time/rdf/time-prov.ttl
+++ b/time/rdf/time-prov.ttl
@@ -13,9 +13,6 @@
 @prefix time-prov: <http://www.w3.org/2006/time/prov#> .
 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
 
-time:inXSDDateTimeStamp
-  rdfs:subPropertyOf time:inXSDDateTime ;
-.
 <http://www.w3.org/2006/time/prov>
   rdf:type owl:Ontology ;
   dc:creator "Simon J D Cox" ;