diff --git a/ontology/saref4wear.ttl b/ontology/saref4wear.ttl
index 9802908530bbc352782359010d830be34b9413da..83134188763eacf75dd3c6795ba9dc3073bb89d0 100644
--- a/ontology/saref4wear.ttl
+++ b/ontology/saref4wear.ttl
@@ -604,10 +604,6 @@ 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 .