diff --git a/CHANGELOG.md b/CHANGELOG.md
index 75a9e93..9fbd321 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,9 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## [2.5.1] - 2023-02-28
+- Fixed: variable not deserialized in some cases
+
 ## [2.5.0] - 2022-04-05
 - Changed: reduced number of database call in list module (Attention! event details and hasDetails attribute are now callback functions as in contao core)
 - Fixed: some deprecations and imports
diff --git a/classes/EventFilterHelper.php b/classes/EventFilterHelper.php
index 310fe5c..07c613e 100644
--- a/classes/EventFilterHelper.php
+++ b/classes/EventFilterHelper.php
@@ -11,6 +11,7 @@
 
 namespace HeimrichHannot\CalendarPlus;
 
+use Contao\StringUtil;
 use HeimrichHannot\Haste\Cache\FileCache;
 
 class EventFilterHelper extends \Frontend
@@ -53,6 +54,8 @@ public static function getHostSelectOptions(\DataContainer $dc)
     {
         $arrItems = [];
 
+        $dc->objModule->cal_calendar = StringUtil::deserialize($dc->objModule->cal_calendar);
+
         if (!is_array($dc->objModule->cal_calendar) || empty($dc->objModule->cal_calendar))
         {
             return $arrItems;
@@ -113,6 +116,8 @@ public static function getDocentSelectOptions(\DataContainer $dc)
     {
         $arrItems = [];
 
+        $dc->objModule->cal_calendar = StringUtil::deserialize($dc->objModule->cal_calendar);
+
         if (!is_array($dc->objModule->cal_calendar) || empty($dc->objModule->cal_calendar))
         {
             return $arrItems;
@@ -261,6 +266,8 @@ public static function getEventTypesSelectOptions(\DataContainer $dc)
     {
         $arrItems = [];
 
+        $dc->objModule->cal_calendar = StringUtil::deserialize($dc->objModule->cal_calendar);
+
         if (!is_array($dc->objModule->cal_calendar) || empty($dc->objModule->cal_calendar))
         {
             return $arrItems;
@@ -302,6 +309,8 @@ public static function getPromoterSelectOptions(\DataContainer $dc)
     {
         $arrItems = [];
 
+        $dc->objModule->cal_calendar = StringUtil::deserialize($dc->objModule->cal_calendar);
+
         if (!is_array($dc->objModule->cal_calendar) || empty($dc->objModule->cal_calendar))
         {
             return $arrItems;
@@ -337,6 +346,8 @@ public static function getCitySelectOptions(\DataContainer $dc)
     {
         $arrItems = [];
 
+        $dc->objModule->cal_calendar = StringUtil::deserialize($dc->objModule->cal_calendar);
+
         if (!is_array($dc->objModule->cal_calendar) || empty($dc->objModule->cal_calendar))
         {
             return $arrItems;
diff --git a/classes/EventsPlus.php b/classes/EventsPlus.php
index a3343bc..f39d755 100644
--- a/classes/EventsPlus.php
+++ b/classes/EventsPlus.php
@@ -53,6 +53,7 @@ public function getPossibleFilterOptions($objModule)
         $strClass = \Module::findClass($objModule->type);
 
         if (class_exists($strClass)) {
+            /** @var ModuleEventFilter $objFilterModule */
             $objFilterModule = new $strClass($objModule);
             $arrOptions      = $objFilterModule->getFilterOptions();
         }