diff --git a/src/Wallabag/CoreBundle/Controller/WallabagRestController.php b/src/Wallabag/CoreBundle/Controller/WallabagRestController.php
index 3cfb8a778..e9cd8c939 100644
--- a/src/Wallabag/CoreBundle/Controller/WallabagRestController.php
+++ b/src/Wallabag/CoreBundle/Controller/WallabagRestController.php
@@ -33,7 +33,7 @@ class WallabagRestController extends Controller
             throw $this->createNotFoundException();
         }
 
-        return array($user->getSalt());
+        return array($user->getSalt() ?: null);
     }
     /**
      * Retrieve all entries. It could be filtered by many options.
diff --git a/src/Wallabag/CoreBundle/Tests/Controller/WallabagRestControllerTest.php b/src/Wallabag/CoreBundle/Tests/Controller/WallabagRestControllerTest.php
index 298cf10c1..815903fad 100644
--- a/src/Wallabag/CoreBundle/Tests/Controller/WallabagRestControllerTest.php
+++ b/src/Wallabag/CoreBundle/Tests/Controller/WallabagRestControllerTest.php
@@ -35,6 +35,7 @@ class WallabagRestControllerTest extends WallabagTestCase
         $client = $this->createClient();
         $client->request('GET', '/api/salts/admin.json');
         $this->assertEquals(200, $client->getResponse()->getStatusCode());
+        $this->assertNotEmpty(json_decode($client->getResponse()->getContent()));
 
         $client->request('GET', '/api/salts/notfound.json');
         $this->assertEquals(404, $client->getResponse()->getStatusCode());