diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index 9210e41..1a04252 100755
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -247,7 +247,7 @@ final class ApiController extends Controller
         $doc->category    = new NullWikiCategory($request->getDataInt('category') ?? 1);
         $doc->app         = new NullWikiApp($request->getDataInt('app') ?? 1);
         $doc->version     = $request->getDataString('version') ?? '';
-        $doc->setLanguage((string) ($request->getDataString('language') ?? $request->getLanguage()));
+        $doc->setLanguage((string) ($request->getDataString('language') ?? $request->header->l11n->language));
         $doc->setStatus($request->getDataInt('status') ?? WikiStatus::INACTIVE);
 
         if (!empty($tags = $request->getDataJson('tags'))) {
@@ -379,7 +379,7 @@ final class ApiController extends Controller
         $l11nWikiCategory      = new BaseStringL11n();
         $l11nWikiCategory->ref = $request->getDataInt('category') ?? 0;
         $l11nWikiCategory->setLanguage(
-            $request->getDataString('language') ?? $request->getLanguage()
+            $request->getDataString('language') ?? $request->header->l11n->language
         );
         $l11nWikiCategory->content = $request->getDataString('name') ?? '';
 
@@ -527,7 +527,7 @@ final class ApiController extends Controller
         $category->app = new NullWikiApp($request->getDataInt('app') ?? 1);
         $category->setL11n(
             $request->getDataString('name') ?? '',
-            $request->getDataString('language') ?? $request->getLanguage()
+            $request->getDataString('language') ?? $request->header->l11n->language
         );
 
         if ($request->hasData('parent')) {
@@ -620,7 +620,7 @@ final class ApiController extends Controller
 
         $category->setL11n(
             $request->getDataString('name') ?? $category->getL11n(),
-            $request->getDataString('language') ?? $request->getLanguage()
+            $request->getDataString('language') ?? $request->header->l11n->language
         );
 
         return $category;
diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index 179b274..925a811 100755
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -86,7 +86,7 @@ final class BackendController extends Controller
             ->with('name')
             ->where('parent', $request->getDataInt('category'))
             ->where('app', $app)
-            ->where('name/language', $response->getLanguage())
+            ->where('name/language', $response->header->l11n->language)
             ->execute();
 
         $view->setData('categories', $categories);
@@ -96,8 +96,8 @@ final class BackendController extends Controller
             ->with('tags')
             ->with('tags/title')
             ->where('app', $app)
-            ->where('language', $response->getLanguage())
-            ->where('tags/title/language', $response->getLanguage())
+            ->where('language', $response->header->l11n->language)
+            ->where('tags/title/language', $response->header->l11n->language)
             ->limit(25)->sort('createdAt', OrderType::DESC)
             ->execute();
 
@@ -207,7 +207,7 @@ final class BackendController extends Controller
         $view->addData('nav', $this->app->moduleManager->get('Navigation')->createNavigationMid(1005901001, $request, $response));
 
         /** @var \Modules\Knowledgebase\Models\WikiCategory[] $list */
-        $list = WikiCategoryMapper::getAll()->with('name')->where('app', $app)->where('name/language', $response->getLanguage())->execute();
+        $list = WikiCategoryMapper::getAll()->with('name')->where('app', $app)->where('name/language', $response->header->l11n->language)->execute();
         $view->setData('categories', $list);
 
         return $view;
@@ -312,8 +312,8 @@ final class BackendController extends Controller
             ->with('tags/title')
             ->with('media')
             ->where('id', (int) $request->getData('id'))
-            ->where('language', $request->getLanguage())
-            ->where('tags/title/language', $response->getLanguage())
+            ->where('language', $request->header->l11n->language)
+            ->where('tags/title/language', $response->header->l11n->language)
             ->execute();
 
         $accountId = $request->header->account;
@@ -334,7 +334,7 @@ final class BackendController extends Controller
             ->with('name')
             ->where('parent', $request->getDataInt('category'))
             ->where('app', $app)
-            ->where('name/language', $response->getLanguage())
+            ->where('name/language', $response->header->l11n->language)
             ->execute();
 
         $view->setData('categories', $categories);