diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index 3de3898..531cf28 100755
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -622,7 +622,7 @@ final class ApiController extends Controller
      */
     public function apiSettingsDesignSet(RequestAbstract $request, ResponseAbstract $response, $data = null) : void
     {
-        $uploadedFiles = $request->getFiles() ?? [];
+        $uploadedFiles = $request->getFiles();
 
         if (!empty($uploadedFiles)) {
             $upload                   = new UploadFile();
@@ -674,7 +674,7 @@ final class ApiController extends Controller
         // handle app installation
         $result = $appManager->install(
             __DIR__ . '/../../../' . $app,
-            __DIR__ . '/../../../' . $request->getData('appDest') ?? '',
+            __DIR__ . '/../../../' . ($request->getData('appDest') ?? ''),
             $request->getData('theme') ?? 'Default'
         );
 
@@ -1114,7 +1114,7 @@ final class ApiController extends Controller
                     $this->app->l11nServer === null ? $request->header->l11n->jsonSerialize() : $this->app->l11nServer->jsonSerialize()
                 );
         } else {
-            $locale = \explode('_', $request->getData('locale') ?? '');
+            $locale = \explode('_', $request->getData('locale'));
 
             $account->l11n
                 ->loadFromLanguage(
diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index f5189ed..23f86ef 100755
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -462,7 +462,7 @@ final class BackendController extends Controller
         $module = $request->getData('id') ?? '';
         $view->setData('module', $module);
 
-        $appPath      = __DIR__ . '/../../../Web';
+        $appPath     = __DIR__ . '/../../../Web';
         $activeHooks = [];
 
         $apps = \scandir($appPath);
diff --git a/Models/AccountCredentialMapper.php b/Models/AccountCredentialMapper.php
index 77671a7..979ef22 100644
--- a/Models/AccountCredentialMapper.php
+++ b/Models/AccountCredentialMapper.php
@@ -27,7 +27,7 @@ final class AccountCredentialMapper extends AccountMapper
     /**
      * Columns.
      *
-     * @var array<string, array<string, bool|string|array>>
+     * @var array<string, array{name:string, type:string, internal:string, autocomplete?:bool, readonly?:bool, writeonly?:bool, annotations?:array}>
      * @since 1.0.0
      */
     public const COLUMNS = [
diff --git a/Models/AccountMapper.php b/Models/AccountMapper.php
index 130544b..1022ede 100755
--- a/Models/AccountMapper.php
+++ b/Models/AccountMapper.php
@@ -32,7 +32,7 @@ class AccountMapper extends DataMapperFactory
     /**
      * Columns.
      *
-     * @var array<string, array<string, bool|string|array>>
+     * @var array<string, array{name:string, type:string, internal:string, autocomplete?:bool, readonly?:bool, writeonly?:bool, annotations?:array}>
      * @since 1.0.0
      */
     public const COLUMNS = [
diff --git a/Models/AppMapper.php b/Models/AppMapper.php
index ae0b8dd..825b42f 100644
--- a/Models/AppMapper.php
+++ b/Models/AppMapper.php
@@ -29,7 +29,7 @@ final class AppMapper extends DataMapperFactory
     /**
      * Columns.
      *
-     * @var array<string, array<string, bool|string|array>>
+     * @var array<string, array{name:string, type:string, internal:string, autocomplete?:bool, readonly?:bool, writeonly?:bool, annotations?:array}>
      * @since 1.0.0
      */
     public const COLUMNS = [
diff --git a/composer.json b/composer.json
index b90cb5e..10044a1 100755
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
         "friendsofphp/php-cs-fixer": ">=3.2",
         "squizlabs/php_codesniffer": ">=3.6",
         "phpmd/phpmd": ">=2.9",
-        "phpstan/phpstan": ">=0.12.58",
+        "phpstan/phpstan": ">=1.5.4",
         "phan/phan": ">=3.2.6"
     },
     "minimum-stability": "dev",