diff --git a/core/lib/Drupal/Core/Plugin/DefaultSinglePluginBag.php b/core/lib/Drupal/Core/Plugin/DefaultSinglePluginBag.php
index 561dc99..2bfb612 100644
--- a/core/lib/Drupal/Core/Plugin/DefaultSinglePluginBag.php
+++ b/core/lib/Drupal/Core/Plugin/DefaultSinglePluginBag.php
@@ -9,6 +9,7 @@
 
 use Drupal\Component\Plugin\PluginBag;
 use Drupal\Component\Plugin\PluginManagerInterface;
+use Drupal\Component\Utility\MapArray;
 
 /**
  * Provides a default plugin bag for a plugin type.
@@ -47,7 +48,7 @@ class DefaultSinglePluginBag extends PluginBag {
    */
   public function __construct(PluginManagerInterface $manager, array $instance_ids, array $configuration) {
     $this->manager = $manager;
-    $this->instanceIDs = drupal_map_assoc($instance_ids);
+    $this->instanceIDs = MapArray::copyValuesToKeys($instance_ids);
     $this->configuration = $configuration;
   }