diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index 2e3123a..d26787c 100755
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -123,7 +123,7 @@ final class ApiController extends Controller
         }
 
         $tag = $this->createTagFromRequest($request);
-        $tag->setL11n($request->getDataString('title') ?? '', $request->getDataString('language') ?? $request->getLanguage());
+        $tag->setL11n($request->getDataString('title') ?? '', $request->getDataString('language') ?? $request->header->l11n->language);
         $this->createModel($request->header->account, $tag, TagMapper::class, 'tag', $request->getOrigin());
 
         $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Tag', 'Tag successfully created', $tag);
@@ -210,7 +210,7 @@ final class ApiController extends Controller
         $tagL11n      = new BaseStringL11n();
         $tagL11n->ref = $request->getDataInt('tag') ?? 0;
         $tagL11n->setLanguage(
-            $request->getDataString('language') ?? $request->getLanguage()
+            $request->getDataString('language') ?? $request->header->l11n->language
         );
         $tagL11n->content = $request->getDataString('title') ?? '';
 
@@ -276,7 +276,7 @@ final class ApiController extends Controller
         /** @var \Modules\Tag\Models\Tag[] $tags */
         $tags = TagMapper::getAll()
             ->with('title')
-            ->where('title/language', $request->getLanguage())
+            ->where('title/language', $request->header->l11n->language)
             ->where('title/content', '%' . ($request->getDataString('search') ?? '') . '%', 'LIKE')
             ->execute();
 
diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index 31cbf59..f842fac 100755
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -78,7 +78,7 @@ final class BackendController extends Controller
                 TagMapper::getAll()
                     ->with('title')
                     ->where('id', $request->getDataInt('id') ?? 0, '<')
-                    ->where('title/language', $request->getLanguage())
+                    ->where('title/language', $request->header->l11n->language)
                     ->limit(25)
                     ->execute()
             );
@@ -87,7 +87,7 @@ final class BackendController extends Controller
                 TagMapper::getAll()
                     ->with('title')
                     ->where('id', $request->getDataInt('id') ?? 0, '>')
-                    ->where('title/language', $request->getLanguage())
+                    ->where('title/language', $request->header->l11n->language)
                     ->limit(25)
                     ->execute()
             );
@@ -96,7 +96,7 @@ final class BackendController extends Controller
                 TagMapper::getAll()
                     ->with('title')
                     ->where('id', 0, '>')
-                    ->where('title/language', $request->getLanguage())
+                    ->where('title/language', $request->header->l11n->language)
                     ->limit(25)
                     ->execute()
             );
@@ -125,7 +125,7 @@ final class BackendController extends Controller
         $tag = TagMapper::get()
             ->with('title')
             ->where('id', (int) $request->getData('id'))
-            ->where('title/language', $response->getLanguage())
+            ->where('title/language', $response->header->l11n->language)
             ->execute();
 
         $view->setTemplate('/Modules/Tag/Theme/Backend/tag-single');
diff --git a/tests/Models/TagL11nMapperTest.php b/tests/Models/TagL11nMapperTest.php
index fed452d..ce6a62b 100755
--- a/tests/Models/TagL11nMapperTest.php
+++ b/tests/Models/TagL11nMapperTest.php
@@ -51,6 +51,6 @@ final class TagL11nMapperTest extends \PHPUnit\Framework\TestCase
 
         $l11nR = TagL11nMapper::get()->where('id', $l11n->id)->execute();
         self::assertEquals($l11n->content, $l11nR->content);
-        self::assertEquals($l11n->getLanguage(), $l11nR->getLanguage());
+        self::assertEquals($l11n->language, $l11nR->getLanguage());
     }
 }