diff --git a/core/lib/Drupal/Core/Field/Entity/BaseFieldOverride.php b/core/lib/Drupal/Core/Field/Entity/BaseFieldOverride.php
index f20f3a5..b31833a 100644
--- a/core/lib/Drupal/Core/Field/Entity/BaseFieldOverride.php
+++ b/core/lib/Drupal/Core/Field/Entity/BaseFieldOverride.php
@@ -143,6 +143,13 @@ public function isComputed() {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function getClass() {
+    return $this->getBaseFieldDefinition()->getClass();
+  }
+
+  /**
    * Gets the base field definition.
    *
    * @return \Drupal\Core\Field\BaseFieldDefinition