diff --git a/src/cco-extensions/ModalRelationOntology.ttl b/src/cco-extensions/ModalRelationOntology.ttl
index b432438..41e1123 100644
--- a/src/cco-extensions/ModalRelationOntology.ttl
+++ b/src/cco-extensions/ModalRelationOntology.ttl
@@ -962,7 +962,7 @@ mro:ont00001801 rdf:type owl:ObjectProperty ;
                 owl:inverseOf mro:ont00001808 ;
                 rdfs:range cco:ont00000958 ;
                 rdfs:label "is subject of"@en ;
-                <http://www.w3.org/2004/02/skos/core#definition> "x is_subject_of y iff x is an instance of Entity and y is an instance of Information Content Entity such that the information content of y depends on the existence of x. A primitive relationship."@en ;
+                <http://www.w3.org/2004/02/skos/core#definition> "x is_subject_of y iff x is an instance of Entity and y is an instance of Information Content Entity and y is_about x."@en ;
                 cco:ont00001760 <https://www.commoncoreontologies.org/ModalRelationOntology> .