diff --git a/core/lib/Drupal/Core/Menu/ContextualLinkManager.php b/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
index c8ccc34..2624726 100644
--- a/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
+++ b/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
@@ -39,7 +39,7 @@ class ContextualLinkManager extends DefaultPluginManager {
     // The default link options.
     'options' => array(),
     // The weight of the link.
-    'weight' => 0,
+    'weight' => NULL,
     // Default class for contextual link implementations.
     'class' => '\Drupal\Core\Menu\ContextualLinkDefault',
     // The plugin id. Set by the plugin system based on the top-level YAML key.