diff --git a/typo3/sysext/indexed_search/Classes/Controller/SearchController.php b/typo3/sysext/indexed_search/Classes/Controller/SearchController.php
index 23e7382f0469698e19584e3fe1c4abac733c189e..ecf1c0cbc6de0ffa7727a73bf66969587d73f365 100644
--- a/typo3/sysext/indexed_search/Classes/Controller/SearchController.php
+++ b/typo3/sysext/indexed_search/Classes/Controller/SearchController.php
@@ -419,7 +419,7 @@ class SearchController extends ActionController
             $this->resultSections = [];
             foreach ($sections as $id => $resultRows) {
                 $rlParts = explode('-', $id);
-                if ($rlParts[2]) {
+                if ($rlParts[2] ?? false) {
                     $theId = $rlParts[2];
                     $theRLid = 'rl2_' . $rlParts[2];
                 } elseif ($rlParts[1]) {