diff --git a/AgentOntology.ttl b/AgentOntology.ttl
index f15952f..84d0d10 100644
--- a/AgentOntology.ttl
+++ b/AgentOntology.ttl
@@ -177,7 +177,7 @@ cco:has_daughter_in_law rdf:type owl:ObjectProperty ;
 
 
 ###  http://www.ontologyrepository.com/CommonCoreOntologies/has_familial_relationship_to
-cco:has_familial_relationship_to rdf:type owl:ObjectProperty ;
+cco:has_familial_relationship_to rdf:type owl:ObjectProperty, owl:SymmetricProperty ;
                                  rdfs:domain cco:Person ;
                                  rdfs:range cco:Person ;
                                  cco:definition "A relationship between persons by virtue of ancestry or legal union."@en ;