diff --git a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
index be416d7..c3817d1 100644
--- a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -21,13 +21,6 @@ class MigrateUpgradeForm extends ConfirmFormBase {
   use MigrationConfigurationTrait;
 
   /**
-   * Mapping of known migrations and their source and destination modules.
-   *
-   * @var array[]
-   */
-  protected $moduleUpgradePaths = [];
-
-  /**
    * The state service.
    *
    * @var \Drupal\Core\State\StateInterface
@@ -408,27 +401,29 @@ public function buildConfirmForm(array $form, FormStateInterface $form_state) {
       $migration_id = $migration->getPluginId();
 
       // Determine the source provider, looking at configuration first.
-      $source_module = (!empty($migration->getSourceConfiguration()['provider'])) ? $migration->getSourceConfiguration()['provider'] : NULL;
+      $source_configuration = $migration->getSourceConfiguration();
+      $source_module = (!empty($source_configuration['provider'])) ? $source_configuration['provider'] : NULL;
       if (!$source_module) {
-        $source_module = (!empty($migration->getSourcePlugin()
-          ->getPluginDefinition()['source_provider'])) ? $migration->getSourcePlugin()
-          ->getPluginDefinition()['source_provider'] : NULL;
+        $plugin_definition = $migration->getSourcePlugin()->getPluginDefinition();
+        $source_module = (!empty($plugin_definition['source_provider'])) ? $plugin_definition['source_provider'] : NULL;
       }
       if (!$source_module) {
         drupal_set_message(t('Source provider not found for @migration_id.', ['@migration_id' => $migration_id]), 'error');
       }
 
       // Determine the destination provider.
-      $destination_module = (!empty($migration->getDestinationConfiguration()['provider'])) ? $migration->getDestinationConfiguration()['provider'] : NULL;
+      $destination_configuration = $migration->getDestinationConfiguration();
+      $destination_module = (!empty($destination_configuration['provider'])) ? $destination_configuration['provider'] : NULL;
       if (!$destination_module) {
-        if ($migration->getDestinationPlugin()->getPluginId() == 'config') {
-          $configuration_destination = (!empty($migration->getDestinationConfiguration()['config_name'])) ? $migration->getDestinationConfiguration()['config_name'] : NULL;
+        $destination_plugin = $migration->getDestinationPlugin();
+        if ($destination_plugin->getPluginId() == 'config') {
+          $configuration_destination = (!empty($destination_configuration['config_name'])) ? $destination_configuration['config_name'] : NULL;
           if ($configuration_destination) {
             $destination_module = explode('.', $configuration_destination, 2)[0];
           }
         }
         else {
-          $destination_module = $migration->getDestinationPlugin()->getPluginDefinition()['provider'];
+          $destination_module = $destination_plugin->getPluginDefinition()['provider'];
         }
       }
       if (!$destination_module) {
@@ -436,8 +431,6 @@ public function buildConfirmForm(array $form, FormStateInterface $form_state) {
       }
 
       if ($source_module && $destination_module) {
-        $this->moduleUpgradePaths[$migration_id]['source_module'] = $source_module;
-        $this->moduleUpgradePaths[$migration_id]['destination_module'] = $destination_module;
         $table_data[$source_module][$destination_module][$migration_id] = $migration->label();
       }
     }