diff --git a/CHANGELOG.md b/CHANGELOG.md
index 71e904df..9d208f02 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Fix `json_decode` using class with namespace
 - Fix drag and drop
 - Increased the maximum length of the language column to support longer locale codes
 
diff --git a/hook.php b/hook.php
index c38b7619..86f11568 100644
--- a/hook.php
+++ b/hook.php
@@ -338,7 +338,7 @@ function plugin_datainjection_populate_fields()
     $container = new PluginFieldsContainer();
     $found     = $container->find(['is_active' => 1]);
     foreach ($found as $values) {
-        $types = json_decode($values['itemtypes']);
+        $types = PluginFieldsToolbox::decodeJSONItemtypes($values['itemtypes']);
 
         foreach ($types as $type) {
             $classname                    = PluginFieldsContainer::getClassname($type, $values['name'], 'Injection');
diff --git a/inc/container.class.php b/inc/container.class.php
index e6ccd70c..5baa4c80 100644
--- a/inc/container.class.php
+++ b/inc/container.class.php
@@ -172,7 +172,7 @@ public static function installBaseData(Migration $migration, $version)
             foreach ($result as $type) {
                 $migration_genericobject_itemtype[$type['itemtype']] = [
                     'genericobject_itemtype' => $type['itemtype'],
-                    'itemtype' => 'Glpi\CustomAsset\\' . $type['name'] . 'Asset',
+                    'itemtype' => 'Glpi\\\\CustomAsset\\\\' . $type['name'] . 'Asset',
                     'genericobject_name' => $type['name'],
                     'name' => $type['name'] . 'Asset',
                 ];
@@ -191,7 +191,7 @@ public static function installBaseData(Migration $migration, $version)
             $container_class = new self();
             foreach ($result as $container) {
                 self::generateTemplate($container);
-                foreach (json_decode($container['itemtypes']) as $itemtype) {
+                foreach (PluginFieldsToolbox::decodeJSONItemtypes($container['itemtypes']) as $itemtype) {
                     $classname = self::getClassname($itemtype, $container["name"]);
                     $old_table = $classname::getTable();
                     // Rename genericobject container table
@@ -239,7 +239,7 @@ public static function installUserData(Migration $migration, $version)
         foreach ($containers as $container) {
             $itemtypes = [];
             if (!empty($container['itemtypes'])) {
-                $decoded = json_decode($container['itemtypes'], true);
+                $decoded = PluginFieldsToolbox::decodeJSONItemtypes($container['itemtypes'], true);
                 if (is_array($decoded)) {
                     $itemtypes = $decoded;
                 }
@@ -290,7 +290,7 @@ public static function installUserData(Migration $migration, $version)
 
                 // Update container name
                 $new_name = $toolbox->getSystemNameFromLabel($container['label']);
-                foreach (json_decode($container['itemtypes']) as $itemtype) {
+                foreach (PluginFieldsToolbox::decodeJSONItemtypes($container['itemtypes']) as $itemtype) {
                     while (strlen(getTableForItemType(self::getClassname($itemtype, $new_name))) > 64) {
                         // limit tables names to 64 chars (MySQL limit)
                         $new_name = substr($new_name, 0, -1);
@@ -304,7 +304,7 @@ public static function installUserData(Migration $migration, $version)
                 );
 
                 // Rename container tables and itemtype if needed
-                foreach (json_decode($container['itemtypes']) as $itemtype) {
+                foreach (PluginFieldsToolbox::decodeJSONItemtypes($container['itemtypes']) as $itemtype) {
                     $migration->renameItemtype(
                         self::getClassname($itemtype, $old_name),
                         self::getClassname($itemtype, $new_name),
@@ -640,7 +640,7 @@ public function prepareInputForAdd($input)
             $found = $this->find(['type' => 'dom']);
             if (count($found) > 0) {
                 foreach (array_column($found, 'itemtypes') as $founditemtypes) {
-                    foreach (json_decode($founditemtypes) as $founditemtype) {
+                    foreach (PluginFieldsToolbox::decodeJSONItemtypes($founditemtypes) as $founditemtype) {
                         if (in_array($founditemtype, $input['itemtypes'])) {
                             Session::AddMessageAfterRedirect(__("You cannot add several blocks with type 'Insertion in the form' on same object", 'fields'), false, ERROR);
 
@@ -656,7 +656,7 @@ public function prepareInputForAdd($input)
             $found = $this->find(['type' => 'domtab', 'subtype' => $input['subtype']]);
             if (count($found) > 0) {
                 foreach (array_column($found, 'itemtypes') as $founditemtypes) {
-                    foreach (json_decode($founditemtypes) as $founditemtype) {
+                    foreach (PluginFieldsToolbox::decodeJSONItemtypes($founditemtypes) as $founditemtype) {
                         if (in_array($founditemtype, $input['itemtypes'])) {
                             Session::AddMessageAfterRedirect(__("You cannot add several blocks with type 'Insertion in the form of a specific tab' on same object tab", 'fields'), false, ERROR);
 
@@ -688,7 +688,7 @@ public function prepareInputForAdd($input)
         $found = $this->find(['name' => $input['name']]);
         if (count($found) > 0) {
             foreach (array_column($found, 'itemtypes') as $founditemtypes) {
-                foreach (json_decode($founditemtypes) as $founditemtype) {
+                foreach (PluginFieldsToolbox::decodeJSONItemtypes($founditemtypes) as $founditemtype) {
                     if (in_array($founditemtype, $input['itemtypes'])) {
                         Session::AddMessageAfterRedirect(__('You cannot add several blocs with identical name on same object', 'fields'), false, ERROR);
 
@@ -781,7 +781,7 @@ public function pre_deleteItem()
 
         $_SESSION['delete_container'] = true;
 
-        foreach (json_decode($this->fields['itemtypes']) as $itemtype) {
+        foreach (PluginFieldsToolbox::decodeJSONItemtypes($this->fields['itemtypes']) as $itemtype) {
             $classname          = self::getClassname($itemtype, $this->fields['name']);
             $sysname            = self::getSystemName($itemtype, $this->fields['name']);
             $class_filename     = $sysname . '.class.php';
@@ -843,7 +843,7 @@ public static function preItemPurge($item)
         $containers         = new self();
         $founded_containers = $containers->find();
         foreach ($founded_containers as $container) {
-            $itemtypes = json_decode($container['itemtypes']);
+            $itemtypes = PluginFieldsToolbox::decodeJSONItemtypes($container['itemtypes']);
             if (in_array($itemtype, $itemtypes)) {
                 $classname = 'PluginFields' . $itemtype . getSingular($container['name']);
                 $classname = preg_replace('/s{2}$/i', 's', $classname); // in case name ends with 'ss' remove last 's'
@@ -928,7 +928,7 @@ public function showForm($ID, $options = [])
         echo '<td>' . __('Associated item type') . ' : </td>';
         echo '<td>';
         if ($ID > 0) {
-            $types = json_decode($this->fields['itemtypes']);
+            $types = PluginFieldsToolbox::decodeJSONItemtypes($this->fields['itemtypes']);
             $obj   = '';
             $count = count($types);
             $i     = 1;
@@ -969,7 +969,7 @@ public function showForm($ID, $options = [])
         echo '<td>';
         echo "&nbsp;<span id='subtype_$rand'></span>";
         if ($ID > 0 && !empty($this->fields['subtype'])) {
-            $itemtypes = json_decode($this->fields['itemtypes'], true);
+            $itemtypes = PluginFieldsToolbox::decodeJSONItemtypes($this->fields['itemtypes'], true);
             $itemtype  = array_shift($itemtypes);
             $dbu = new DbUtils();
             $item = $dbu->getItemForItemtype($itemtype);
@@ -1234,7 +1234,7 @@ public function getTabNameForItem(CommonGLPI $item, $withtemplate = 0)
             foreach ($itemtypes[$item->getType()] as $tab_name => $tab_label) {
                 // needs to check if entity of item is in hierachy of $tab_name
                 foreach ($container->find(['is_active' => 1, 'name' => $tab_name]) as $data) {
-                    $dataitemtypes = json_decode($data['itemtypes']);
+                    $dataitemtypes = PluginFieldsToolbox::decodeJSONItemtypes($data['itemtypes']);
                     if (in_array(get_class($item), $dataitemtypes) != false) {
                         $entities = [$data['entities_id']];
                         if ($data['is_recursive']) {
@@ -1266,7 +1266,7 @@ public static function displayTabContentForItem(CommonGLPI $item, $tabnum = 1, $
         //retrieve container for current tab
         $container = new self();
         if ($container->getFromDB($tabnum)) {
-            $dataitemtypes = json_decode($container->fields['itemtypes']);
+            $dataitemtypes = PluginFieldsToolbox::decodeJSONItemtypes($container->fields['itemtypes']);
             if (in_array(get_class($item), $dataitemtypes) != false) {
                 return PluginFieldsField::showForTabContainer($container->fields['id'], $item);
             }
@@ -2243,7 +2243,7 @@ public function prepareInputForClone($input)
         if (array_key_exists('itemtypes', $input) && !empty($input['itemtypes'])) {
             // $input has been transformed with `Toolbox::addslashes_deep()`, and `self::prepareInputForAdd()`
             // is expecting an array, so it have to be unslashed then json decoded.
-            $input['itemtypes'] = json_decode($input['itemtypes']);
+            $input['itemtypes'] = PluginFieldsToolbox::decodeJSONItemtypes($input['itemtypes']);
         } else {
             unset($input['itemtypes']);
         }
diff --git a/inc/field.class.php b/inc/field.class.php
index 95f249c2..659f2743 100644
--- a/inc/field.class.php
+++ b/inc/field.class.php
@@ -302,7 +302,7 @@ public function prepareInputForAdd($input)
         if ($input['type'] !== 'header') {
             $container_obj = new PluginFieldsContainer();
             $container_obj->getFromDB($input['plugin_fields_containers_id']);
-            foreach (json_decode($container_obj->fields['itemtypes']) as $itemtype) {
+            foreach (PluginFieldsToolbox::decodeJSONItemtypes($container_obj->fields['itemtypes']) as $itemtype) {
                 $classname = PluginFieldsContainer::getClassname($itemtype, $container_obj->fields['name']);
                 $classname::addField(
                     $input['name'],
@@ -354,7 +354,7 @@ public function pre_deleteItem()
         $container_obj = new PluginFieldsContainer();
         $container_obj->getFromDB($this->fields['plugin_fields_containers_id']);
 
-        foreach (json_decode($container_obj->fields['itemtypes']) as $itemtype) {
+        foreach (PluginFieldsToolbox::decodeJSONItemtypes($container_obj->fields['itemtypes']) as $itemtype) {
             $so = PluginFieldsContainer::getAddSearchOptions($itemtype, $this->fields['plugin_fields_containers_id']);
             foreach ($so as $so_id => $so_value) {
                 if ($this->fields['type'] == 'glpi_item') {
@@ -380,7 +380,7 @@ public function pre_deleteItem()
             && !isset($_SESSION['uninstall_fields'])
             && !isset($_SESSION['delete_container'])
         ) {
-            foreach (json_decode($container_obj->fields['itemtypes']) as $itemtype) {
+            foreach (PluginFieldsToolbox::decodeJSONItemtypes($container_obj->fields['itemtypes']) as $itemtype) {
                 $classname = PluginFieldsContainer::getClassname($itemtype, $container_obj->fields['name']);
                 $classname::removeField($this->fields['name'], $this->fields['type']);
             }
@@ -400,7 +400,7 @@ public function pre_deleteItem()
 
             $use_by_another = false;
             foreach ($all_container as $container_fields) {
-                foreach (json_decode($container_fields['itemtypes']) as $itemtype) {
+                foreach (PluginFieldsToolbox::decodeJSONItemtypes($container_fields['itemtypes']) as $itemtype) {
                     $dropdown_classname = PluginFieldsDropdown::getClassname($this->fields['name']);
                     $classname = PluginFieldsContainer::getClassname($itemtype, $container_fields['name']);
                     $dropdown_fk = getForeignKeyFieldForItemType($dropdown_classname);
diff --git a/setup.php b/setup.php
index 51dc8a11..6336098f 100644
--- a/setup.php
+++ b/setup.php
@@ -305,7 +305,7 @@ function plugin_fields_exportBlockAsYaml($container_id = null)
         $containers    = $container_obj->find($where);
         foreach ($containers as $container) {
             $itemtypes = (strlen($container['itemtypes']) > 0)
-                ? json_decode($container['itemtypes'], true)
+                ? PluginFieldsToolbox::decodeJSONItemtypes($container['itemtypes'], true)
                 : [];
 
             foreach ($itemtypes as $itemtype) {