diff --git a/app/Repos/EntityRepo.php b/app/Repos/EntityRepo.php
index 25d229be1..944c0bcfc 100644
--- a/app/Repos/EntityRepo.php
+++ b/app/Repos/EntityRepo.php
@@ -553,7 +553,7 @@ class EntityRepo
      */
     protected function nameToSlug($name)
     {
-        $slug = str_replace(' ', '-', function_exists('mb_strtolower') ? mb_strtolower($name) : strtolower($name));
+        $slug = str_replace(' ', '-', mb_strtolower($name));
         $slug = preg_replace('/[\+\/\\\?\@\}\{\.\,\=\[\]\#\&\!\*\'\;\:\$\%]/', '', $slug);
         if ($slug === "") $slug = substr(md5(rand(1, 500)), 0, 5);
         return $slug;
diff --git a/tests/Entity/EntityTest.php b/tests/Entity/EntityTest.php
index 07f1926c5..3f23475a0 100644
--- a/tests/Entity/EntityTest.php
+++ b/tests/Entity/EntityTest.php
@@ -257,4 +257,15 @@ class EntityTest extends BrowserKitTest
             ->seeInElement('#recently-updated-pages', $page->name);
     }
 
+    public function test_slug_multi_byte_lower_casing()
+    {
+        $entityRepo = app(EntityRepo::class);
+        $book = $entityRepo->createFromInput('book', [
+            'name' => 'КНИГА'
+        ]);
+
+        $this->assertEquals('книга', $book->slug);
+    }
+
+
 }