diff --git a/platform/workspace/storage/src/com/intellij/platform/workspace/storage/impl/WorkspaceEntityExtensionDelegate.kt b/platform/workspace/storage/src/com/intellij/platform/workspace/storage/impl/WorkspaceEntityExtensionDelegate.kt
index 5d7326ec6395..af4538202f12 100644
--- a/platform/workspace/storage/src/com/intellij/platform/workspace/storage/impl/WorkspaceEntityExtensionDelegate.kt
+++ b/platform/workspace/storage/src/com/intellij/platform/workspace/storage/impl/WorkspaceEntityExtensionDelegate.kt
@@ -57,12 +57,6 @@ public open class WorkspaceEntityExtensionDelegate<T> {
     return result as T
   }
 
-  public operator fun setValue(thisRef: WorkspaceEntity, property: KProperty<*>, value: T?) {
-    thisRef as ModifiableWorkspaceEntityBase<*, *>
-    val entities = if (value is List<*>) value else listOf(value)
-    thisRef.updateReferenceToEntity(property.returnTypeKClass.java, property.isChildProperty, entities as List<WorkspaceEntity?>)
-  }
-
   private fun computeOrGetCachedMetadata(property: KProperty<*>): PropertyMetadata {
     val cachesMetadata = calculatedCache[property]
     if (cachesMetadata != null) return cachesMetadata