diff --git a/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php b/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php
index b488250..3f54a58 100644
--- a/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php
+++ b/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php
@@ -131,17 +131,13 @@ public function getConfiguration() {
    * {@inheritdoc}
    */
   public function setConfiguration($configuration) {
-    $this->configurations = array();
-    $this->pluginInstances = array();
-    $this->instanceIDs = array();
-
-    $instance_ids = array_keys($configuration);
-    $this->instanceIDs = array_combine($instance_ids, $instance_ids);
-    // Store the original order of the instance IDs for export.
-    $this->originalOrder = $this->instanceIDs;
-
+    $instance_ids = $this->getInstanceIds();
     foreach ($configuration as $instance_id => $instance_configuration) {
       $this->setInstanceConfiguration($instance_id, $instance_configuration);
+      unset($instance_ids[$instance_id]);
+    }
+    foreach ($instance_ids as $instance_id) {
+      $this->removeInstanceId($instance_id);
     }
     return $this;
   }