diff --git a/plugins/search-indexer-backend/src/types.ts b/plugins/search-indexer-backend/src/types.ts
index f9c2c0a263..63a10be2ea 100644
--- a/plugins/search-indexer-backend/src/types.ts
+++ b/plugins/search-indexer-backend/src/types.ts
@@ -36,7 +36,7 @@ export interface IndexableDocument {
   location: string;
 
   /**
-   * The owner of the document (e.g. spec.owner on a catalog entity).
+   * (Optional) The owner of the document (e.g. spec.owner on a catalog entity).
    */
   owner?: string;