diff --git a/src/Action.php b/src/Action.php
index c78965f..843060d 100644
--- a/src/Action.php
+++ b/src/Action.php
@@ -36,7 +36,7 @@ use ArrayObject;
  */
 abstract class Action
 {
-    /** @var array<string>  Current module */
+    /** @var array<string,mixed>  Current module */
     protected $module = [];
 
     /** @var string     Current full path */
@@ -87,7 +87,7 @@ abstract class Action
 
         $settings = dcCore::app()->blog->settings->get(Core::id())->get('settings_' . $this->class_name);
         if (null != $settings) {
-            $settings = unserialize($settings);
+            $settings = json_decode($settings, true);
         }
         $this->settings = is_array($settings) ? $settings : [];
 
@@ -237,7 +237,7 @@ abstract class Action
     {
         dcCore::app()->blog->settings->get(Core::id())->put(
             'settings_' . $this->class_name,
-            serialize($this->settings),
+            json_encode($this->settings),
             'string',
             null,
             true,
diff --git a/src/Core.php b/src/Core.php
index cff7d60..dd5ef3a 100644
--- a/src/Core.php
+++ b/src/Core.php
@@ -79,6 +79,11 @@ class Core
         return basename(dirname(__DIR__));
     }
 
+    public static function name()
+    {
+        return __('improve');
+    }
+
     public function getLogs(): array
     {
         return $this->logs;
@@ -95,8 +100,8 @@ class Core
             return 0;
         }
         $cur            = dcCore::app()->con->openCursor(dcCore::app()->prefix . dcLog::LOG_TABLE_NAME);
-        $cur->log_msg   = serialize($this->logs);
-        $cur->log_table = 'improve';
+        $cur->log_msg   = json_encode($this->logs);
+        $cur->log_table = self::id();
         $id             = dcCore::app()->log->addLog($cur);
 
         return $id;
@@ -104,13 +109,13 @@ class Core
 
     public function readLogs(int $id): array
     {
-        $rs = dcCore::app()->log->getLogs(['log_table' => 'improve', 'log_id' => $id, 'limit' => 1]);
+        $rs = dcCore::app()->log->getLogs(['log_table' => self::id(), 'log_id' => $id, 'limit' => 1]);
         if ($rs->isEmpty()) {
             return [];
         }
         dcCore::app()->log->delLogs($rs->__get('log_id'));
 
-        $res = unserialize($rs->__get('log_msg'));
+        $res = json_decode($rs->__get('log_msg'), true);
 
         return is_array($res) ? $res : [];
     }
@@ -122,7 +127,7 @@ class Core
             return [];
         }
         $lines = [];
-        foreach ($logs['improve'] as $path => $tools) {
+        foreach ($logs[self::id()] as $path => $tools) {
             $l_types = [];
             foreach (['success', 'warning', 'error'] as $type) {
                 $l_tools = [];
@@ -198,7 +203,7 @@ class Core
         }
         foreach ($workers as $action) {
             // trace all path and action in logs
-            $this->logs['improve'][__('Begin')][] = $action->id();
+            $this->logs[self::id()][__('Begin')][] = $action->id();
             // info: set current module
             $action->setModule($module);
             $action->setPath(__('Begin'), '', true);
@@ -215,7 +220,7 @@ class Core
             }
             foreach ($workers as $action) {
                 // trace all path and action in logs
-                $this->logs['improve'][$file[0]][] = $action->id();
+                $this->logs[self::id()][$file[0]][] = $action->id();
                 // info: set current path
                 $action->setPath($file[0], $file[1], $file[2]);
             }
@@ -254,7 +259,7 @@ class Core
         }
         foreach ($workers as $action) {
             // trace all path and action in logs
-            $this->logs['improve'][__('End')][] = $action->id();
+            $this->logs[self::id()][__('End')][] = $action->id();
             // info: set current module
             $action->setPath(__('End'), '', true);
             // action: close module
diff --git a/src/Install.php b/src/Install.php
index 9da1345..8c3af44 100644
--- a/src/Install.php
+++ b/src/Install.php
@@ -16,6 +16,7 @@ namespace Dotclear\Plugin\improve;
 
 /* dotclear */
 use dcCore;
+use dcNamespace;
 use dcNsProcess;
 
 /* php */
@@ -33,7 +34,7 @@ class Install extends dcNsProcess
     private static $default_settings = [[
         'disabled',
         'List of hidden action modules',
-        'tab;newline;endoffile',
+        'cssheader;tab;newline;endoffile',
         'string',
     ]];
 
@@ -52,6 +53,7 @@ class Install extends dcNsProcess
 
         try {
             self::update_0_8_0();
+            self::update_1_1_0();
             self::putSettings();
 
             return true;
@@ -88,4 +90,31 @@ class Install extends dcNsProcess
             }
         }
     }
+
+    /** Update improve < 1.1 : use json_(en|de)code rather than (un)serialize */
+    private static function update_1_1_0(): void
+    {
+        if (version_compare(dcCore::app()->getVersion(Core::id()) ?? '0', '1.1', '<')) {
+            foreach (['setting_', 'preferences'] as $key) {
+                $record = dcCore::app()->con->select(
+                    'SELECT * FROM ' . dcCore::app()->prefix . dcNamespace::NS_TABLE_NAME . ' ' .
+                    "WHERE setting_ns = '" . dcCore::app()->con->escape(Core::id()) . "' " .
+                    "AND setting_id LIKE '" . $key . "%' "
+                );
+
+                while ($record->fetch()) {
+                    try {
+                        $value              = @unserialize($record->f('setting_value'));
+                        $cur                = dcCore::app()->con->openCursor(dcCore::app()->prefix . dcNamespace::NS_TABLE_NAME);
+                        $cur->setting_value = json_encode(is_array($value) ? $value : []);
+                        $cur->update(
+                            "WHERE setting_id = '" . $record->f('setting_id') . "' and setting_ns = '" . dcCore::app()->con->escape($record->f('setting_ns')) . "' " .
+                            'AND blog_id ' . (null === $record->f('blog_id') ? 'IS NULL ' : ("= '" . dcCore::app()->con->escape($record->f('blog_id')) . "' "))
+                        );
+                    } catch(Exception) {
+                    }
+                }
+            }
+        }
+    }
 }
diff --git a/src/Manage.php b/src/Manage.php
index ed9c868..a536d1b 100644
--- a/src/Manage.php
+++ b/src/Manage.php
@@ -89,7 +89,7 @@ class Manage extends dcNsProcess
             if (!empty(self::$type)) {
                 $preferences = dcCore::app()->blog->settings->get(Core::id())->get('preferences');
                 if (is_string($preferences)) {
-                    $preferences = unserialize($preferences);
+                    $preferences = json_decode($preferences, true);
                     if (is_array($preferences)) {
                         return $all ? $preferences : (array_key_exists(self::$type, $preferences) ? $preferences[self::$type] : []);
                     }