diff --git a/ontology/saref4wear.ttl b/ontology/saref4wear.ttl
index d7a0601312e8cc1346898263d73830c02c26e574..8b006d753e19c69186235fb4f7e24c8c971ffb6b 100644
--- a/ontology/saref4wear.ttl
+++ b/ontology/saref4wear.ttl
@@ -605,10 +605,6 @@ s4city:Event rdf:type owl:Class ;
              rdfs:subClassOf [ rdf:type owl:Restriction ;
                                owl:onProperty s4city:takesPlaceAtFacility ;
                                owl:allValuesFrom s4city:Facility
-                             ] ,
-                             [ rdf:type owl:Restriction ;
-                               owl:onProperty s4wear:hasSensor ;
-                               owl:allValuesFrom saref:Sensor
                              ] ;
              rdfs:isDefinedBy s4city: ;
              rdfs:label "Event"@en .