diff --git a/plugins/search-indexer-backend/src/types.ts b/plugins/search-indexer-backend/src/types.ts
index 90529e2101..c4db1ee565 100644
--- a/plugins/search-indexer-backend/src/types.ts
+++ b/plugins/search-indexer-backend/src/types.ts
@@ -90,7 +90,7 @@ export interface RegisterDecoratorParameters {
   decorator: IndexableDocumentDecorator;
 
   /**
-   * An optional array of document types that the given decorator should apply to. If none are provided,
+   * (Optional) An array of document types that the given decorator should apply to. If none are provided,
    * the decorator will be applied to all types.
    */
   types?: string[];