diff --git a/lib/Service/LangRepository.php b/lib/Service/LangRepository.php
index c998a7e..bc124bd 100644
--- a/lib/Service/LangRepository.php
+++ b/lib/Service/LangRepository.php
@@ -26,7 +26,7 @@ class LangRepository
         $qb = $this->db->getQueryBuilder();
 
         $qb->select($qb->createFunction('DISTINCT configvalue'))
-            ->where('configkey="lang" and appid="core" and configvalue<>"en"')
+            ->where('configkey=\'lang\' and appid=\'core\' and configvalue<>\'en\'')
             ->from('preferences')
         ;