How to use SPARQL to CONSTRUCT owl:Restriction

Question

I am trying to create OWL restrictions on some instances in my ontology. These instances are associated to classes via rdf:type relationships when they should be some kind of owl restriction. To solve this, I created a CONSTRUCT statement:

PREFIX myontology:<http://myontology.org/myonto/>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
CONSTRUCT {
  ?entity rdf:type ?owlRestriction .
  ?owlRestriction a owl:Restriction .
  ?owlRestriction owl:onProperty myontology:someRelation .
  ?owlRestriction owl:someValuesFrom ?someClass .
}

WHERE {
  ?owlRestriction a owl:Restriction .
  ?entity a ?class .
  ?class rdfs:subClassOf* myontology:someSuperClass .
}

When I run this, however, the restriction created includes every subclass underneath the myontology:someSuperClass. How can I change the above query such that only the classes directly related to my instances via rdf:type get changed to restrictions?

Thank you for your help!