diff --git a/core/modules/migrate/src/Plugin/MigratePluginManager.php b/core/modules/migrate/src/Plugin/MigratePluginManager.php
index 38982c5..68ac392 100644
--- a/core/modules/migrate/src/Plugin/MigratePluginManager.php
+++ b/core/modules/migrate/src/Plugin/MigratePluginManager.php
@@ -63,15 +63,4 @@ public function createInstance($plugin_id, array $configuration = [], MigrationI
     return $plugin;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function processDefinition(&$definition, $plugin_id) {
-    parent::processDefinition($definition, $plugin_id);
-
-    if (empty($definition['id'])) {
-      throw new InvalidPluginDefinitionException($plugin_id, sprintf('The %s plugin should define the %s property.', $definition['class'], 'id'));
-    }
-  }
-
 }
diff --git a/core/modules/migrate/src/Plugin/migrate/destination/NullDestination.php b/core/modules/migrate/src/Plugin/migrate/destination/NullDestination.php
index 83644f2..c4bd6f3 100644
--- a/core/modules/migrate/src/Plugin/migrate/destination/NullDestination.php
+++ b/core/modules/migrate/src/Plugin/migrate/destination/NullDestination.php
@@ -11,7 +11,7 @@
  * @MigrateDestination(
  *   id = "null",
  *   requirements_met = false,
- *   destination_module = "-1",
+ *   destination_module = "/dev/null",
  * )
  */
 class NullDestination extends DestinationBase {
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
index 7307bad..ab18d82 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
@@ -54,7 +54,9 @@ public function testProvidersExist() {
       $destination_module = $migration->getDestinationPlugin()->getDestinationModule();
       $migration_id = $migration->getPluginId();
       $this->assertTrue($source_module, new FormattableMarkup('Source module found for @migration_id.', ['@migration_id' => $migration_id]));
+      $this->assertInternalType('string', $source_module);
       $this->assertTrue($destination_module, new FormattableMarkup('Destination module found for @migration_id.', ['@migration_id' => $migration_id]));
+      $this->assertInternalType('string', $destination_module);
       // Destination module can't be migrate or migrate_drupal or migrate_drupal_ui
       $invalid_destinations = ['migrate', 'migrate_drupal', 'migrate_drupal_ui'];
       $this->assertNotContains($destination_module, $invalid_destinations, new FormattableMarkup('Invalid destination for @migration_id.', ['@migration_id' => $migration_id]));