diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index 04ee950..aecc176 100644
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -41,7 +41,7 @@ final class BackendController extends Controller
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewProjectList(RequestAbstract $request, ResponseAbstract $response, $data = null) : RenderableInterface
+    public function viewProjectList(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         $view = new View($this->app->l11nManager, $request, $response);
         $view->setTemplate('/Modules/ResearchDevelopment/Theme/Backend/rnd-list');
@@ -62,7 +62,7 @@ final class BackendController extends Controller
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewProjectCreate(RequestAbstract $request, ResponseAbstract $response, $data = null) : RenderableInterface
+    public function viewProjectCreate(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         $view = new View($this->app->l11nManager, $request, $response);
         $view->setTemplate('/Modules/ResearchDevelopment/Theme/Backend/rnd-create');