diff --git a/app/Console/Commands/RegisterApp.php b/app/Console/Commands/RegisterApp.php
index c10a7a35..cff18228 100644
--- a/app/Console/Commands/RegisterApp.php
+++ b/app/Console/Commands/RegisterApp.php
@@ -59,7 +59,7 @@ class RegisterApp extends Command
      * @param bool $remove
      * @return void
      */
-    public function addApp($folder, bool $remove = false)
+    public function addApp($folder, bool $remove = false): void
     {
         $json = app_path('SupportedApps/'.$folder.'/app.json');
 
@@ -98,7 +98,7 @@ class RegisterApp extends Command
      * @param $icon
      * @return void
      */
-    private function saveIcon($appFolder, $icon)
+    private function saveIcon($appFolder, $icon): void
     {
         $iconPath = app_path('SupportedApps/' . $appFolder . '/' . $icon);
         $contents = file_get_contents($iconPath);
diff --git a/app/Http/Controllers/Auth/LoginController.php b/app/Http/Controllers/Auth/LoginController.php
index 02f4dcc4..dcf6d59c 100644
--- a/app/Http/Controllers/Auth/LoginController.php
+++ b/app/Http/Controllers/Auth/LoginController.php
@@ -135,7 +135,7 @@ class LoginController extends Controller
      *
      * @return Application|Factory|View
      */
-    public function showLoginForm()
+    public function showLoginForm(): \Illuminate\View\View
     {
         return view('auth.login');
     }
diff --git a/app/Http/Controllers/Auth/RegisterController.php b/app/Http/Controllers/Auth/RegisterController.php
index 8d8d3053..3c4fd440 100644
--- a/app/Http/Controllers/Auth/RegisterController.php
+++ b/app/Http/Controllers/Auth/RegisterController.php
@@ -60,7 +60,7 @@ class RegisterController extends Controller
      * @param  array  $data
      * @return User
      */
-    protected function create(array $data)
+    protected function create(array $data): User
     {
         return User::create([
             'name' => $data['name'],
diff --git a/app/Http/Controllers/ItemController.php b/app/Http/Controllers/ItemController.php
index 77f7baa4..84d4d3f9 100644
--- a/app/Http/Controllers/ItemController.php
+++ b/app/Http/Controllers/ItemController.php
@@ -511,7 +511,7 @@ class ItemController extends Controller
     /**
      * @return \Illuminate\Contracts\Foundation\Application|RedirectResponse|Redirector
      */
-    public function checkAppList()
+    public function checkAppList(): RedirectResponse
     {
         ProcessApps::dispatch();
         $route = route('items.index');
diff --git a/app/Http/Controllers/ItemRestController.php b/app/Http/Controllers/ItemRestController.php
index d147d8a8..ff908e4a 100644
--- a/app/Http/Controllers/ItemRestController.php
+++ b/app/Http/Controllers/ItemRestController.php
@@ -20,7 +20,7 @@ class ItemRestController extends Controller
      *
      * @return Collection
      */
-    public function index()
+    public function index(): Collection
     {
         $columns = [
             'title',
@@ -70,7 +70,7 @@ class ItemRestController extends Controller
      * @param Item $item
      * @return Response
      */
-    public function show(Item $item)
+    public function show(Item $item): Response
     {
         //
     }
@@ -81,7 +81,7 @@ class ItemRestController extends Controller
      * @param Item $item
      * @return Response
      */
-    public function edit(Item $item)
+    public function edit(Item $item): Response
     {
         //
     }
@@ -93,7 +93,7 @@ class ItemRestController extends Controller
      * @param Item $item
      * @return Response
      */
-    public function update(Request $request, Item $item)
+    public function update(Request $request, Item $item): Response
     {
         //
     }
@@ -104,7 +104,7 @@ class ItemRestController extends Controller
      * @param Item $item
      * @return Response
      */
-    public function destroy(Item $item)
+    public function destroy(Item $item): Response
     {
         //
     }
diff --git a/app/Http/Controllers/TagController.php b/app/Http/Controllers/TagController.php
index 1b65a824..4460bce4 100644
--- a/app/Http/Controllers/TagController.php
+++ b/app/Http/Controllers/TagController.php
@@ -22,7 +22,7 @@ class TagController extends Controller
      *
      * @return Application|Factory|View
      */
-    public function index(Request $request)
+    public function index(Request $request): \Illuminate\View\View
     {
         $trash = (bool) $request->input('trash');
 
@@ -40,7 +40,7 @@ class TagController extends Controller
      *
      * @return Application|Factory|View
      */
-    public function create()
+    public function create(): \Illuminate\View\View
     {
         $data = [];
 
diff --git a/app/Http/Controllers/UserController.php b/app/Http/Controllers/UserController.php
index 256cd0d8..b426878b 100644
--- a/app/Http/Controllers/UserController.php
+++ b/app/Http/Controllers/UserController.php
@@ -41,7 +41,7 @@ class UserController extends Controller
         return view('users.create', $data);
     }
 
-    public function selectUser()
+    public function selectUser(): \Illuminate\View\View
     {
         Auth::logout();
         $data['users'] = User::all();
diff --git a/app/Item.php b/app/Item.php
index 76a8be7c..e89943a2 100644
--- a/app/Item.php
+++ b/app/Item.php
@@ -79,7 +79,7 @@ class Item extends Model
     /**
      * @return void
      */
-    protected static function boot()
+    protected static function boot(): void
     {
         parent::boot();
 
diff --git a/app/Jobs/UpdateApps.php b/app/Jobs/UpdateApps.php
index e034ae81..77b6eb9d 100644
--- a/app/Jobs/UpdateApps.php
+++ b/app/Jobs/UpdateApps.php
@@ -53,7 +53,7 @@ class UpdateApps implements ShouldQueue, ShouldBeUnique
     /**
      * @return void
      */
-    public function failed($exception)
+    public function failed($exception): void
     {
         Cache::lock('updateApps')->forceRelease();
     }
diff --git a/app/Providers/AppServiceProvider.php b/app/Providers/AppServiceProvider.php
index ed917bbc..21bfa6f1 100644
--- a/app/Providers/AppServiceProvider.php
+++ b/app/Providers/AppServiceProvider.php
@@ -108,7 +108,7 @@ class AppServiceProvider extends ServiceProvider
      *
      * @return void
      */
-    public function genKey()
+    public function genKey(): void
     {
         if (is_file(base_path('.env'))) {
             if (empty(env('APP_KEY'))) {
@@ -188,7 +188,7 @@ class AppServiceProvider extends ServiceProvider
     /**
      * @return void
      */
-    private function updateApps()
+    private function updateApps(): void
     {
         // This lock ensures that the job is not invoked multiple times.
         // In 5 minutes all app updates should be finished.
diff --git a/app/Providers/RouteServiceProvider.php b/app/Providers/RouteServiceProvider.php
index 8c99db06..76c28314 100644
--- a/app/Providers/RouteServiceProvider.php
+++ b/app/Providers/RouteServiceProvider.php
@@ -32,7 +32,7 @@ class RouteServiceProvider extends ServiceProvider
      *
      * @return void
      */
-    public function map()
+    public function map(): void
     {
         $this->mapApiRoutes();
 
@@ -48,7 +48,7 @@ class RouteServiceProvider extends ServiceProvider
      *
      * @return void
      */
-    protected function mapWebRoutes()
+    protected function mapWebRoutes(): void
     {
         Route::middleware('web')
              ->group(base_path('routes/web.php'));
@@ -61,7 +61,7 @@ class RouteServiceProvider extends ServiceProvider
      *
      * @return void
      */
-    protected function mapApiRoutes()
+    protected function mapApiRoutes(): void
     {
         Route::prefix('api')
              ->middleware('api')
diff --git a/app/Setting.php b/app/Setting.php
index be1adbb4..243a1adf 100644
--- a/app/Setting.php
+++ b/app/Setting.php
@@ -224,7 +224,7 @@ class Setting extends Model
      *
      * @return mixed
      */
-    public static function _fetch($key, $user = null)
+    public static function _fetch(string $key, $user = null)
     {
         // @codingStandardsIgnoreEnd
         //$cachekey = ($user === null) ? $key : $key.'-'.$user->id;
@@ -270,7 +270,7 @@ class Setting extends Model
      * @param string $key
      * @param $value
      */
-    public static function add($key, $value)
+    public static function add(string $key, $value)
     {
         self::$cache[$key] = $value;
     }
@@ -280,7 +280,7 @@ class Setting extends Model
      *
      * @return bool
      */
-    public static function cached($key): bool
+    public static function cached(string $key): bool
     {
         return array_key_exists($key, self::$cache);
     }
diff --git a/database/factories/UserFactory.php b/database/factories/UserFactory.php
index bc3533a3..f5f88257 100644
--- a/database/factories/UserFactory.php
+++ b/database/factories/UserFactory.php
@@ -32,7 +32,7 @@ class UserFactory extends Factory
      *
      * @return \Illuminate\Database\Eloquent\Factories\Factory
      */
-    public function unverified()
+    public function unverified(): Factory
     {
         return $this->state(function (array $attributes) {
             return [