diff --git a/core/lib/Drupal/Core/Field/BundleFieldDefinition.php b/core/lib/Drupal/Core/Field/BundleFieldDefinition.php
new file mode 100644
index 0000000..b72d323
--- /dev/null
+++ b/core/lib/Drupal/Core/Field/BundleFieldDefinition.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\Core\Field;
+
+use Drupal\Core\Cache\UnchangingCacheableDependencyTrait;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Field\Entity\BaseFieldOverride;
+use Drupal\Core\Field\TypedData\FieldItemDataDefinition;
+use Drupal\Core\TypedData\ListDataDefinition;
+use Drupal\Core\TypedData\OptionsProviderInterface;
+
+/**
+ * A class for defining entity bundle fields.
+ */
+class BundleFieldDefinition extends BaseFieldDefinition {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isBaseField() {
+    return FALSE;
+  }
+
+}
diff --git a/core/modules/system/tests/modules/entity_test/src/FieldStorageDefinition.php b/core/modules/system/tests/modules/entity_test/src/FieldStorageDefinition.php
index 1a37d63..1cb4658 100644
--- a/core/modules/system/tests/modules/entity_test/src/FieldStorageDefinition.php
+++ b/core/modules/system/tests/modules/entity_test/src/FieldStorageDefinition.php
@@ -2,7 +2,7 @@
 
 namespace Drupal\entity_test;
 
-use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\Core\Field\BundleFieldDefinition;
 
 /**
  * A custom field storage definition class.
@@ -12,14 +12,8 @@
  *
  * @todo Provide and make use of a proper FieldStorageDefinition class instead:
  *   https://www.drupal.org/node/2280639.
+ *
+ * @deprecated in Drupal 8.5.0 and will be removed before Drupal 9.0.0.
+ *   Use \Drupal\Core\Field\BundleFieldDefinition instead.
  */
-class FieldStorageDefinition extends BaseFieldDefinition {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function isBaseField() {
-    return FALSE;
-  }
-
-}
+class FieldStorageDefinition extends BundleFieldDefinition {}