diff --git a/lib/public/FullTextSearch/Model/IIndex.php b/lib/public/FullTextSearch/Model/IIndex.php
index 1a8b5d875ba..dad10c934de 100644
--- a/lib/public/FullTextSearch/Model/IIndex.php
+++ b/lib/public/FullTextSearch/Model/IIndex.php
@@ -84,6 +84,17 @@ interface IIndex {
 	public function getDocumentId(): string;
 
 
+	/**
+	 * Get the collection of the index.
+	 * If empty (''), means collection is the default one used by the internal framework
+	 *
+	 * @since 24.0.0
+	 *
+	 * @return string
+	 */
+	public function getCollection(): string;
+
+
 	/**
 	 * Set the source of the original document.
 	 *