diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c9a62c6..34ece948 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fix for the `COALESCE` part of the `SQL query` for `multiple` dropdowns
 - Fix `search option` for `multiple` dropdown
 - Fix display from Planning view
+- Fix `classname` resolution when multiple `s` at end of container name
 
 ## [1.21.23] - 2025-08-26
 
diff --git a/inc/container.class.php b/inc/container.class.php
index d6750d44..3968e27e 100644
--- a/inc/container.class.php
+++ b/inc/container.class.php
@@ -768,6 +768,7 @@ public static function preItemPurge($item)
             $itemtypes = json_decode($container['itemtypes']);
             if (in_array($itemtype, $itemtypes)) {
                 $classname = 'PluginFields' . $itemtype . getSingular($container['name']);
+                $classname = preg_replace('/s{2}$/i', 's', $classname); // in case name ends with 'ss' remove last 's'
                 $fields    = new $classname();
                 $fields->deleteByCriteria(['items_id' => $item->fields['id']], true);
             }