diff --git a/src/cco-modules/AgentOntology.ttl b/src/cco-modules/AgentOntology.ttl
index d414b91..6e9dc37 100644
--- a/src/cco-modules/AgentOntology.ttl
+++ b/src/cco-modules/AgentOntology.ttl
@@ -191,7 +191,7 @@ cco:ont00001798 rdf:type owl:ObjectProperty ;
                  rdfs:domain cco:ont00001262 ;
                  rdfs:range cco:ont00001262 ;
                  rdfs:label "is supervised by"@en ;
-                 skos:definition "A person p1 is supervised by a person p2 by virtue of p1 being directed, managed, or overseen by p2."@en ;
+                 skos:definition "x is_supervised_by y iff x and y are both instances of Person and y supervises x."@en ;
                  cco:ont00001754 "http://en.wiktionary.org/wiki/supervise)" ;
                  cco:ont00001760 "https://www.commoncoreontologies.org/AgentOntology"^^xsd:anyURI .