diff --git a/themes/bootstrap5/js/lightbox.js b/themes/bootstrap5/js/lightbox.js
index ec7efcdc500..f3ae6607c4c 100644
--- a/themes/bootstrap5/js/lightbox.js
+++ b/themes/bootstrap5/js/lightbox.js
@@ -369,8 +369,8 @@ VuFind.register('lightbox', function Lightbox() {
     // remove nodes on whose click, the modal closes
     var nodesWhichAreNotCloseTargets = focusableNodes.filter(function nodeFilter(node) {
       return !node.hasAttribute("data-lightbox-close") && (
-        !node.hasAttribute("data-dismiss") ||
-        node.getAttribute("data-dismiss") !== "modal"
+        !node.hasAttribute("data-bs-dismiss") ||
+        node.getAttribute("data-bs-dismiss") !== "modal"
       );
     });