diff --git a/config/cache.php b/config/cache.php
index 753d24e527..6ab9c78955 100644
--- a/config/cache.php
+++ b/config/cache.php
@@ -102,5 +102,5 @@ return [
     |
     */
 
-    'prefix' => env('CACHE_PREFIX', Str::slug(env('APP_NAME', 'laravel'), '_').'_cache_'),
+    'prefix' => env('CACHE_PREFIX', Str::slug((string) env('APP_NAME', 'laravel'), '_').'_cache_'),
 ];
diff --git a/config/database.php b/config/database.php
index 4af5e0bb71..da6e829fe7 100644
--- a/config/database.php
+++ b/config/database.php
@@ -145,7 +145,7 @@ return [
 
         'options' => [
             'cluster' => env('REDIS_CLUSTER', 'redis'),
-            'prefix' => env('REDIS_PREFIX', Str::slug(env('APP_NAME', 'laravel'), '_').'_database_'),
+            'prefix' => env('REDIS_PREFIX', Str::slug((string) env('APP_NAME', 'laravel'), '_').'_database_'),
             'persistent' => env('REDIS_PERSISTENT', false),
         ],
 
diff --git a/config/session.php b/config/session.php
index bda9b7790c..8ac1858799 100644
--- a/config/session.php
+++ b/config/session.php
@@ -130,7 +130,7 @@ return [
 
     'cookie' => env(
         'SESSION_COOKIE',
-        Str::slug(env('APP_NAME', 'laravel'), '_').'_session',
+        Str::slug((string) env('APP_NAME', 'laravel'), '_').'_session',
     ),
 
     /*