diff --git a/.config/redis.config.php b/.config/redis.config.php
index 5df799f2..170f7b6c 100644
--- a/.config/redis.config.php
+++ b/.config/redis.config.php
@@ -5,8 +5,9 @@ if (getenv('REDIS_HOST')) {
     'memcache.locking' => '\OC\Memcache\Redis',
     'redis' => array(
       'host' => getenv('REDIS_HOST'),
-      'port' => getenv('REDIS_HOST_PORT') ?: 6379,
     ),
   );
+  if (getenv('REDIS_HOST_PORT') !== false) {
+    $CONFIG['redis']['port'] = getenv('REDIS_HOST_PORT');
+  }
 }
-