diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index 2f98dad..8fb8385 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -162,7 +162,7 @@ function hook_cron() {
  *   - primitive type: (optional) Maps the data type to one of the pre-defined
  *     primitive types in \Drupal\Core\TypedData\Primitive. If set, it must be
  *     a constant defined by \Drupal\Core\TypedData\Primitive such as
- *     \Drupal\Core\TypedData\Primitive::String.
+ *     \Drupal\Core\TypedData\Primitive::STRING.
  *   - constraints: An array of validation constraints for this type. See
  *     \Drupal\Core\TypedData\TypedDataManager::getConstraints() for details.
  *
@@ -175,7 +175,7 @@ function hook_data_type_info() {
     'email' => array(
       'label' => t('Email'),
       'class' => '\Drupal\email\Type\Email',
-      'primitive type' => \Drupal\Core\TypedData\Primitive::String,
+      'primitive type' => \Drupal\Core\TypedData\Primitive::STRING,
       'constraints' => array('Email' => array()),
     ),
   );
@@ -1803,7 +1803,7 @@ function hook_template_preprocess_default_variables_alter(&$variables) {
  * @return
  *   The machine-readable name of the theme that should be used for the current
  *   page request. The value returned from this function will only have an
- *   effect if it corresponds to a currently-active theme on the site. Do not 
+ *   effect if it corresponds to a currently-active theme on the site. Do not
  *   return a value if you do not wish to set a custom theme.
  */
 function hook_custom_theme() {
@@ -2932,7 +2932,7 @@ function hook_disable() {
  * inspect later. It is important to remove any temporary variables using
  * variable_del() before your last task has completed and control is handed
  * back to the installer.
- * 
+ *
  * @param array $install_state
  *   An array of information about the current installation state.
  *