diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
index 57e4243..34640d4 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
@@ -235,7 +235,7 @@ protected function doSave($id, EntityInterface $entity) {
     }
 
     // Retrieve the desired properties and set them in config.
-    foreach ($entity->toArray() as $key => $value) {
+    foreach ($this->preSaveData($entity->toArray(), $entity) as $key => $value) {
       $config->set($key, $value);
     }
     $config->save();
@@ -244,6 +244,21 @@ protected function doSave($id, EntityInterface $entity) {
   }
 
   /**
+   * Alter data for the storage environment right before saving.
+   *
+   * @param array $data
+   *   Raw configuration data being saved.
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   Entity being saved.
+   *
+   * @return array
+   *   Data to save with any modifications necessary for storage performed.
+   */
+  protected function preSaveData($data, EntityInterface $entity) {
+    return $data;
+  }
+
+  /**
    * {@inheritdoc}
    */
   protected function has($id, EntityInterface $entity) {
diff --git a/core/lib/Drupal/Core/Field/FieldItemBase.php b/core/lib/Drupal/Core/Field/FieldItemBase.php
index 296c468..114b2ee 100644
--- a/core/lib/Drupal/Core/Field/FieldItemBase.php
+++ b/core/lib/Drupal/Core/Field/FieldItemBase.php
@@ -255,4 +255,24 @@ public function instanceSettingsForm(array $form, array &$form_state) {
     return array();
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function preSaveSettings(array &$settings) { }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function postLoadSettings(array &$settings) { }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function preSaveInstanceSettings(array &$settings) { }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function postLoadInstanceSettings(array &$settings) { }
+
 }
diff --git a/core/lib/Drupal/Core/Field/FieldItemInterface.php b/core/lib/Drupal/Core/Field/FieldItemInterface.php
index ee27996..d70d366 100644
--- a/core/lib/Drupal/Core/Field/FieldItemInterface.php
+++ b/core/lib/Drupal/Core/Field/FieldItemInterface.php
@@ -183,6 +183,48 @@ public function view($display_options = array());
   public function preSave();
 
   /**
+   * Defines behavior for transforming field settings before being saved.
+   *
+   * May be used to alter settings to transform them to a storage-friendly form.
+   *
+   * @param array $settings
+   *   Field settings.
+   */
+  public function preSaveSettings(array &$settings);
+
+  /**
+   * Defines custom behavior for transforming field settings when loading.
+   *
+   * May be used to alter settings to transform them from a storage-friendly
+   * form.
+   *
+   * @param array $settings
+   *   Field settings.
+   */
+  public function postLoadSettings(array &$settings);
+
+  /**
+   * Defines behavior for transforming instance settings before being saved.
+   *
+   * May be used to alter settings to transform them to a storage-friendly form.
+   *
+   * @param array $settings
+   *   Field settings.
+   */
+  public function preSaveInstanceSettings(array &$settings);
+
+  /**
+   * Defines custom behavior for transforming instance settings when loading.
+   *
+   * May be used to alter settings to transform them from a storage-friendly
+   * form.
+   *
+   * @param array $settings
+   *   Field settings.
+   */
+  public function postLoadInstanceSettings(array &$settings);
+
+  /**
    * Defines custom insert behavior for field values.
    *
    * This method is called during the process of inserting an entity, just
diff --git a/core/modules/field/src/Entity/FieldConfig.php b/core/modules/field/src/Entity/FieldConfig.php
index af025e3..767e075 100644
--- a/core/modules/field/src/Entity/FieldConfig.php
+++ b/core/modules/field/src/Entity/FieldConfig.php
@@ -720,7 +720,7 @@ public function getUniqueStorageIdentifier() {
   /**
    * Helper to retrieve the field item class.
    */
-  protected function getFieldItemClass() {
+  public function getFieldItemClass() {
     $type_definition = \Drupal::typedDataManager()
       ->getDefinition('field_item:' . $this->getType());
     return $type_definition['class'];
diff --git a/core/modules/field/src/FieldConfigStorage.php b/core/modules/field/src/FieldConfigStorage.php
index 8419424..76566c9 100644
--- a/core/modules/field/src/FieldConfigStorage.php
+++ b/core/modules/field/src/FieldConfigStorage.php
@@ -10,6 +10,7 @@
 use Drupal\Component\Uuid\UuidInterface;
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\Entity\ConfigEntityStorage;
+use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\Query\QueryFactory;
@@ -156,4 +157,35 @@ public function loadByProperties(array $conditions = array()) {
     return $matching_fields;
 
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function postLoad(array &$entities) {
+    foreach ($entities as $entity) {
+      // @todo This needs to modify the entity, so works off of the entity
+      // settings as it believes at the same. Because this came from storage
+      // it would technically be the same as the output of preSaveData() but
+      // philosophically it feels far from it.
+      if (is_array($entity->settings)) {
+        $field_class = $entity->getFieldItemClass();
+        $field_class::postLoadSettings($entity->settings);
+      }
+    }
+
+    parent::postLoad($entities);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function preSaveData($data, EntityInterface $entity) {
+    // @todo This looks ugly as it assumes a settings key which is not codified
+    // on this level otherwise. Also this works in a very different level,
+    // not using the entity anymore to avoid modifying it vs. load.
+    $field_class = $entity->getFieldItemClass();
+    $data['settings'] = $field_class::preSaveSettings($data['settings']);
+    return $data;
+  }
+
 }
diff --git a/core/modules/options/src/Plugin/Field/FieldType/ListItemAllowedValuesTrait.php b/core/modules/options/src/Plugin/Field/FieldType/ListItemAllowedValuesTrait.php
index d10e303..375e8ce 100644
--- a/core/modules/options/src/Plugin/Field/FieldType/ListItemAllowedValuesTrait.php
+++ b/core/modules/options/src/Plugin/Field/FieldType/ListItemAllowedValuesTrait.php
@@ -13,6 +13,24 @@
 trait ListItemAllowedValuesTrait {
 
   /**
+   * Defined in \Drupal\Core\Field\FieldItemInterface.
+   */
+  public static function preSaveSettings(array &$settings) {
+    if (isset($settings['allowed_values'])) {
+      $settings['allowed_values'] = static::structureAllowedValues($settings['allowed_values']);
+    }
+  }
+
+  /**
+   * Defined in \Drupal\Core\Field\FieldItemInterface.
+   */
+  public static function postLoadSettings(array &$settings) {
+    if (isset($settings['allowed_values'])) {
+      $settings['allowed_values'] = static::simplifyAllowedValues($settings['allowed_values']);
+    }
+  }
+
+  /**
    * Simplify allowed values to a key-value array from the structured array.
    *
    * @param array $structured_values
@@ -23,7 +43,7 @@
    *   Allowed values were the array key is the 'value' value, the value is
    *   the 'label' value.
    */
-  public static function simplifyAllowedValues(array $structured_values) {
+  protected static function simplifyAllowedValues(array $structured_values) {
     $values = array();
     foreach ($structured_values as $item) {
       if (is_array($item['label'])) {
@@ -47,7 +67,7 @@ public static function simplifyAllowedValues(array $structured_values) {
    *   Array of items with a 'value' and 'label' key each for the allowed
    *   values.
    */
-  public static function structureAllowedValues(array $values) {
+  protected static function structureAllowedValues(array $values) {
     $structured_values = array();
     foreach ($values as $value => $label) {
       if (is_array($label)) {