diff --git a/config/app.php b/config/app.php
index 9e0e9faa94..ad3d2efa8b 100644
--- a/config/app.php
+++ b/config/app.php
@@ -65,7 +65,7 @@ return [
     |
     */
 
-    'port' => env('APP_PORT', null),
+    'port' => env('APP_PORT', 8000),
 
     /*
     |--------------------------------------------------------------------------
@@ -126,7 +126,7 @@ return [
 
     'previous_keys' => [
         ...array_filter(
-            explode(',', env('APP_PREVIOUS_KEYS', '')),
+            explode(',', (string) env('APP_PREVIOUS_KEYS', '')),
         ),
     ],
 
@@ -144,7 +144,7 @@ return [
     */
 
     'maintenance' => [
-        'driver' => env('APP_MAINTENANCE_DRIVER', 'file'),
-        'store' => env('APP_MAINTENANCE_STORE', 'database'),
+        'driver' => env('APP_MAINTENANCE_DRIVER', 'cache'),
+        'store' => env('APP_MAINTENANCE_STORE', 'redis'),
     ],
 ];