diff --git a/ontology/CASE-unstable-2.0.0.ttl b/ontology/CASE-unstable-2.0.0.ttl
index eb1dcc23..ec74ca15 100644
--- a/ontology/CASE-unstable-2.0.0.ttl
+++ b/ontology/CASE-unstable-2.0.0.ttl
@@ -2835,7 +2835,6 @@ core:ObjectStatusVocab
 	rdfs:label "Object Status Vocabulary"@en-US ;
 	owl:equivalentClass [
 		a rdfs:Datatype ;
-		owl:onDatatype xsd:string ;
 		owl:oneOf (
 			"Draft"^^core:ObjectStatusVocab
 			"Final"^^core:ObjectStatusVocab
diff --git a/ontology/CASE-unstable.ttl b/ontology/CASE-unstable.ttl
index 59497dc1..bd310b93 100644
--- a/ontology/CASE-unstable.ttl
+++ b/ontology/CASE-unstable.ttl
@@ -2796,7 +2796,6 @@ core:ObjectStatusVocab
 	rdfs:label "Object Status Vocabulary"@en-US ;
 	owl:equivalentClass [
 		a rdfs:Datatype ;
-		owl:onDatatype xsd:string ;
 		owl:oneOf (
 			"Draft"^^core:ObjectStatusVocab
 			"Final"^^core:ObjectStatusVocab