diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
index 5a32aa6..c5aed48 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
@@ -39,6 +39,24 @@ public static function propertyDefinitions(FieldDefinitionInterface $field_defin
   /**
    * {@inheritdoc}
    */
+  public function getConstraints() {
+    $constraint_manager = \Drupal::typedDataManager()->getValidationConstraintManager();
+    $constraints = parent::getConstraints();
+
+    $constraints[] = $constraint_manager->create('ComplexData', array(
+      'value' => array(
+        'Length' => array(
+          'max' => $this->getFieldSetting('maxlength'),
+        )
+      ),
+    ));
+
+    return $constraints;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public static function schema(FieldDefinitionInterface $field_definition) {
     return array(
       'columns' => array(
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
index 27ca9e9..1ae55ae 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
@@ -33,4 +33,5 @@ public function applyDefaultValue($notify = TRUE) {
     $this->setValue(array('value' => $uuid->generate()), $notify);
     return $this;
   }
+
 }