diff --git a/src/contracts/Container/Encore/ConfigurationDumper.php b/src/contracts/Container/Encore/ConfigurationDumper.php
index 36fa449f74..1b5ed900fa 100644
--- a/src/contracts/Container/Encore/ConfigurationDumper.php
+++ b/src/contracts/Container/Encore/ConfigurationDumper.php
@@ -31,7 +31,7 @@ public function __construct(ContainerInterface $containerBuilder)
     }
 
     /**
-     * @phpstan-param array<string, array<string, array{?'deprecated': bool, ?'alternative': string}>> $webpackConfigNames
+     * @phpstan-param array<string, array<string, array{'deprecated'?: bool, 'alternative'?: string}>> $webpackConfigNames
      *
      * @throws \JsonException
      */