diff --git a/src/App.php b/src/App.php
index d0c3898..2accbe5 100644
--- a/src/App.php
+++ b/src/App.php
@@ -272,7 +272,7 @@ public function user(string $value = null)
      */
     public function removeService(string $alias): void
     {
-        return $this->remove($alias);
+        $this->remove($alias);
     }
 
     /**
diff --git a/src/Container.php b/src/Container.php
index 43b1582..2f8357e 100644
--- a/src/Container.php
+++ b/src/Container.php
@@ -13,7 +13,7 @@
 class Container
 {
     private array $storage = [];
-    private ?Container $instances = [];
+    private $instances = [];
 
     public static function getInstance()
     {