diff --git a/core/modules/migrate/src/Plugin/migrate/destination/Entity.php b/core/modules/migrate/src/Plugin/migrate/destination/Entity.php
index 8d69f80..a91264d 100644
--- a/core/modules/migrate/src/Plugin/migrate/destination/Entity.php
+++ b/core/modules/migrate/src/Plugin/migrate/destination/Entity.php
@@ -114,10 +114,7 @@ protected function getEntity(Row $row, array $old_destination_id_values) {
       $values = $row->getDestination();
       // Stubs might not have the bundle specified.
       if ($row->stub()) {
-        $bundle_key = $this->getKey('bundle');
-        if ($bundle_key && !isset($values[$bundle_key])) {
-          $values[$bundle_key] = reset($this->bundles);
-        }
+        $this->processStubValues($values);
       }
       $entity = $this->storage->create($values);
       $entity->enforceIsNew();
@@ -126,6 +123,21 @@ protected function getEntity(Row $row, array $old_destination_id_values) {
   }
 
   /**
+   * Process the stub values.
+   *
+   * @param array $values
+   *   An array of destination values.
+   */
+  protected function processStubValues(array $values) {
+    $bundle_key = $this->getKey('bundle');
+    if ($bundle_key && !isset($values[$bundle_key])) {
+      $values[$bundle_key] = reset($this->bundles);
+    }
+
+    $this->migration->set('process', array_intersect_key($this->migration->get('process'), $this->getIds()));
+  }
+
+  /**
    * Returns a specific entity key.
    *
    * @param string $key
diff --git a/core/modules/migrate_drupal/config/install/migrate.migration.d6_comment.yml b/core/modules/migrate_drupal/config/install/migrate.migration.d6_comment.yml
index 31b45f7..dc38654 100644
--- a/core/modules/migrate_drupal/config/install/migrate.migration.d6_comment.yml
+++ b/core/modules/migrate_drupal/config/install/migrate.migration.d6_comment.yml
@@ -4,7 +4,6 @@ migration_groups:
   - Drupal 6
 source:
   plugin: d6_comment
-  timestamp: 0
   constants:
     entity_type: node
 process:
diff --git a/core/modules/migrate_drupal/config/schema/migrate_drupal.source.schema.yml b/core/modules/migrate_drupal/config/schema/migrate_drupal.source.schema.yml
index 3c5d16d..e28173f 100644
--- a/core/modules/migrate_drupal/config/schema/migrate_drupal.source.schema.yml
+++ b/core/modules/migrate_drupal/config/schema/migrate_drupal.source.schema.yml
@@ -40,8 +40,6 @@ migrate.source.d6_comment:
   type: migrate_source_sql
   label: 'Drupal 6 comment'
   mapping:
-    timestamp:
-      type: integer
     constants:
       type: mapping
       label: 'Constants'