diff --git a/dynamic_entity_reference.install b/dynamic_entity_reference.install
index 16e8b1d..7606599 100644
--- a/dynamic_entity_reference.install
+++ b/dynamic_entity_reference.install
@@ -26,7 +26,7 @@ function dynamic_entity_reference_update_8001() {
   $service = \Drupal::service('dynamic_entity_reference.entity_type_subscriber');
   // Only update dynamic_entity_reference fields.
   foreach ($entity_field_manager->getFieldMapByFieldType('dynamic_entity_reference') as $entity_type_id => $map) {
-    $entity_type = $this->entityTypeManager->getDefinition($entity_type_id);
+    $entity_type = $entity_type_manager->getDefinition($entity_type_id);
     $entity_storage = $entity_type_manager->getStorage($entity_type_id);
     // Only SQL storage based entities are supported.
     if ($entity_storage instanceof SqlEntityStorageInterface) {