diff --git a/src/UnicaenAuth/Controller/AuthController.php b/src/UnicaenAuth/Controller/AuthController.php
index 30d274778c75153556a4f347ea4ae55631ea15a9..364ecc0140badfb1bc89efdaeab388d3f153ef83 100644
--- a/src/UnicaenAuth/Controller/AuthController.php
+++ b/src/UnicaenAuth/Controller/AuthController.php
@@ -137,7 +137,7 @@ class AuthController extends AbstractActionController
         $form->initFromRequest($request);
 
         // si le formulaire POSTé ne possède aucun champ identifiant, on va directement à authenticateAction()
-        if ($request->isPost() and ! $request->getPost()->get('identity')) {
+        if ($request->isPost() and ! $request->getPost()->offsetExists('identity')) {
             return $this->redirect()->toRoute('zfcuser/authenticate', [], ['query' => $this->params()->fromQuery()], true);
         }