diff --git a/modules/simple_sitemap_engines/simple_sitemap_engines.install b/modules/simple_sitemap_engines/simple_sitemap_engines.install
index 9c17504..301577f 100644
--- a/modules/simple_sitemap_engines/simple_sitemap_engines.install
+++ b/modules/simple_sitemap_engines/simple_sitemap_engines.install
@@ -11,3 +11,17 @@
 function simple_sitemap_engines_uninstall() {
   \Drupal::service('state')->delete('simple_sitemap_engines_last_submitted');
 }
+
+/**
+ * Remove last_submitted data from config.
+ */
+function simple_sitemap_engines_update_8001() {
+  $engines = \Drupal::entityTypeManager()
+    ->getStorage('simple_sitemap_engine')
+    ->loadMultiple();
+  foreach ($engines as $engine_id => $engine) {
+    $config = \Drupal::configFactory()
+      ->getEditable("simple_sitemap_engines.simple_sitemap_engine.$engine_id");
+    $config->clear('last_submitted')->save();
+  }
+}
diff --git a/modules/simple_sitemap_engines/src/Controller/SearchEngineListBuilder.php b/modules/simple_sitemap_engines/src/Controller/SearchEngineListBuilder.php
index 8ce2b2f..a0cf7b9 100644
--- a/modules/simple_sitemap_engines/src/Controller/SearchEngineListBuilder.php
+++ b/modules/simple_sitemap_engines/src/Controller/SearchEngineListBuilder.php
@@ -64,13 +64,14 @@ class SearchEngineListBuilder extends ConfigEntityListBuilder {
    * {@inheritdoc}
    */
   public function buildRow(EntityInterface $entity) {
+    $state = \Drupal::state();
 
     /** @var \Drupal\simple_sitemap_engines\Entity\SearchEngine $entity */
     $row['label'] = $entity->label();
     $row['url'] = $entity->url;
     $row['variants'] = implode(', ', $entity->sitemap_variants);
-    $row['last_submitted'] = $entity->last_submitted
-      ? $this->dateFormatter->format($entity->last_submitted, 'short')
+    $row['last_submitted'] = $state->get('simple_sitemap_engines_last_submitted', 0)
+      ? $this->dateFormatter->format($state->get('simple_sitemap_engines_last_submitted', 0), 'short')
       : $this->t('Never');
 
     return $row;
diff --git a/modules/simple_sitemap_engines/src/Entity/SearchEngine.php b/modules/simple_sitemap_engines/src/Entity/SearchEngine.php
index 0b1c9a7..937d36c 100644
--- a/modules/simple_sitemap_engines/src/Entity/SearchEngine.php
+++ b/modules/simple_sitemap_engines/src/Entity/SearchEngine.php
@@ -26,7 +26,6 @@ use Drupal\Core\Config\Entity\ConfigEntityBase;
  *     "label",
  *     "url",
  *     "sitemap_variants",
- *     "last_submitted",
  *   }
  * )
  */