diff --git a/console.rst b/console.rst
index af1881f2c5d..bc4e7824862 100644
--- a/console.rst
+++ b/console.rst
@@ -186,6 +186,9 @@ as a service, you can use normal dependency injection. Imagine you have a
         public function __construct(UserManager $userManager)
         {
             $this->userManager = $userManager;
+
+            // you *must* call the parent constructor
+            parent::__construct();
         }
 
         // ...