diff --git a/workbench_moderation.install b/workbench_moderation.install
index a3c08eb..4d36e53 100644
--- a/workbench_moderation.install
+++ b/workbench_moderation.install
@@ -19,11 +19,14 @@ function workbench_moderation_install() {
 
   $entity_definition_update_manager = \Drupal::entityDefinitionUpdateManager();
 
-  $revisionable_entity_defintions = $moderation_info->selectRevisionableEntities((\Drupal::entityTypeManager()->getDefinitions()));
+  $definitions = \Drupal::entityTypeManager()->getDefinitions();
+  $revisionable_entity_defintions = $moderation_info->selectRevisionableEntities($definitions);
 
   /** @var \Drupal\Core\Entity\ContentEntityTypeInterface $type */
   foreach ($revisionable_entity_defintions as $type) {
-    $workbench_moderation_definition = $field_manager->getFieldStorageDefinitions($type->id())['moderation_state'];
-    $entity_definition_update_manager->installFieldStorageDefinition('moderation_state', $type->id(), 'moderation_state', $workbench_moderation_definition);
+    $fields = $field_manager->getFieldStorageDefinitions($type->id());
+    if (isset($fields['moderation_state'])) {
+      $entity_definition_update_manager->installFieldStorageDefinition('moderation_state', $type->id(), 'moderation_state', $fields['moderation_state']);
+    }
   }
 }
diff --git a/workbench_moderation.services.yml b/workbench_moderation.services.yml
index 4d1b3dd..0edbe42 100644
--- a/workbench_moderation.services.yml
+++ b/workbench_moderation.services.yml
@@ -11,9 +11,6 @@ services:
   workbench_moderation.moderation_information:
     class: Drupal\workbench_moderation\ModerationInformation
     arguments: ['@entity_type.manager', '@current_user']
-  workbench_moderation.base_field:
-    class: Drupal\workbench_moderation\BaseFieldInfo
-    arguments: ['@workbench_moderation.moderation_information']
   workbench_moderation.entity_type:
     class: Drupal\workbench_moderation\EntityTypeInfo
     arguments: ['@string_translation', '@workbench_moderation.moderation_information', '@entity_type.manager']