diff --git a/module/VuFind/src/VuFind/View/Helper/Root/Flashmessages.php b/module/VuFind/src/VuFind/View/Helper/Root/Flashmessages.php
index a863a9a702b66226b6a9bb76c7a41510abc536df..1ec7cf97d73c74176182116344097d28275bd293 100644
--- a/module/VuFind/src/VuFind/View/Helper/Root/Flashmessages.php
+++ b/module/VuFind/src/VuFind/View/Helper/Root/Flashmessages.php
@@ -82,7 +82,7 @@ class Flashmessages extends AbstractHelper
             $messages = array_merge(
                 $this->fm->getMessages(), $this->fm->getCurrentMessages()
             );
-            foreach (array_unique($messages) as $msg) {
+            foreach (array_unique($messages, SORT_REGULAR) as $msg) {
                 $html .= '<div class="' . $this->getClassForNamespace($ns) . '">';
                 // Advanced form:
                 if (is_array($msg)) {