diff --git a/webapi/src/main/scala/org/knora/webapi/messages/util/search/gravsearch/transformers/OntologyInferencer.scala b/webapi/src/main/scala/org/knora/webapi/messages/util/search/gravsearch/transformers/OntologyInferencer.scala
index 181f037734..0b69c06acf 100644
--- a/webapi/src/main/scala/org/knora/webapi/messages/util/search/gravsearch/transformers/OntologyInferencer.scala
+++ b/webapi/src/main/scala/org/knora/webapi/messages/util/search/gravsearch/transformers/OntologyInferencer.scala
@@ -43,7 +43,7 @@ final case class OntologyInferencer(
       case None                       => knownSubClasses
       case Some(relevantOntologyIris) =>
         // filter the known subclasses against the relevant ontologies
-        knownSubClasses.filter(cache.classDefinedInOntology.get(_).exists(relevantOntologyIris.contains(_)))
+        knownSubClasses.filter(cache.classDefinedInOntology(_).exists(relevantOntologyIris.contains(_)))
     }
 
     // Searches for a `?v a <subClassIRI>`, or if multiple subclasses are present, then
@@ -68,7 +68,7 @@ final case class OntologyInferencer(
     // if provided, limit the child properties to those that belong to relevant ontologies
     val subProps = limitInferenceToOntologies match {
       case Some(ontologyIris) =>
-        knownSubProps.filter(cache.propertyDefinedInOntology.get(_).exists(ontologyIris.contains(_)))
+        knownSubProps.filter(cache.propertyDefinedInOntology(_).exists(ontologyIris.contains(_)))
       case None => knownSubProps
     }
     // Searches for a `?v <propertyIRI> ?b`, or if multiple propertyIRIs are present, then
diff --git a/webapi/src/main/scala/org/knora/webapi/slice/ontology/repo/model/OntologyCacheData.scala b/webapi/src/main/scala/org/knora/webapi/slice/ontology/repo/model/OntologyCacheData.scala
index c6e152c35e..5257e47ea4 100644
--- a/webapi/src/main/scala/org/knora/webapi/slice/ontology/repo/model/OntologyCacheData.scala
+++ b/webapi/src/main/scala/org/knora/webapi/slice/ontology/repo/model/OntologyCacheData.scala
@@ -28,8 +28,8 @@ case class OntologyCacheData(
   classToSubclassLookup: Map[SmartIri, Set[SmartIri]],
   subPropertyOfRelations: Map[SmartIri, Set[SmartIri]],
   superPropertyOfRelations: Map[SmartIri, Set[SmartIri]],
-  classDefinedInOntology: Map[SmartIri, SmartIri],
-  propertyDefinedInOntology: Map[SmartIri, SmartIri],
+  private val classDefinedInOntology: Map[SmartIri, SmartIri],
+  private val propertyDefinedInOntology: Map[SmartIri, SmartIri],
   private val entityDefinedInOntology: Map[SmartIri, SmartIri],
   private val standoffProperties: Set[SmartIri],
 ) {
@@ -44,7 +44,9 @@ case class OntologyCacheData(
   def getAllStandoffPropertyEntities: Map[SmartIri, ReadPropertyInfoV2] =
     ontologies.values.flatMap(_.properties.view.filterKeys(standoffProperties)).toMap
 
-  def entityDefinedInOntology(propertyIri: SmartIri): Option[SmartIri] = entityDefinedInOntology.get(propertyIri)
+  def entityDefinedInOntology(propertyIri: SmartIri): Option[SmartIri]   = entityDefinedInOntology.get(propertyIri)
+  def classDefinedInOntology(classIri: SmartIri): Option[SmartIri]       = classDefinedInOntology.get(classIri)
+  def propertyDefinedInOntology(propertyIri: SmartIri): Option[SmartIri] = propertyDefinedInOntology.get(propertyIri)
 }
 object OntologyCacheData {
   val Empty = OntologyCacheData(