diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
index 3f7805b..1574059 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
@@ -32,9 +32,10 @@ class UriItem extends StringItem {
    * {@inheritdoc}
    */
   public static function defaultStorageSettings() {
-    return array(
-      'max_length' => 2048,
-    ) + parent::defaultStorageSettings();
+    $storage_settings = parent::defaultStorageSettings();
+    unset($storage_settings['is_ascii']);
+    $storage_settings['max_length'] = 2048;
+    return $storage_settings;
   }
 
   /**
diff --git a/core/modules/field/src/Tests/Uri/UriFieldTest.php b/core/modules/field/src/Tests/Uri/UriFieldTest.php
index 61fd8f3..bf2b704 100644
--- a/core/modules/field/src/Tests/Uri/UriFieldTest.php
+++ b/core/modules/field/src/Tests/Uri/UriFieldTest.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Entity\Entity\EntityViewDisplay;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\Tests\FieldUnitTestBase;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -21,14 +22,7 @@
  *
  * @group field
  */
-class UriFieldTest extends WebTestBase {
-
-  /**
-   * Modules to enable.
-   *
-   * @var array
-   */
-  public static $modules = ['entity_test', 'field_ui', 'options'];
+class UriFieldTest extends FieldUnitTestBase {
 
   /**
    * A field to use in this test class.
@@ -45,20 +39,6 @@ class UriFieldTest extends WebTestBase {
   protected $field;
 
   /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-
-    $this->drupalLogin($this->drupalCreateUser([
-      'view test entity',
-      'administer entity_test content',
-      'administer entity_test form display',
-      'administer entity_test fields',
-    ]));
-  }
-
-  /**
    * Tests URI field.
    */
   public function testUriField() {
@@ -91,13 +71,6 @@ public function testUriField() {
         'type' => 'uri',
       ])
       ->save();
-
-    // Create a display for the full view mode.
-    entity_get_display('entity_test', 'entity_test', 'full')
-      ->setComponent($field_name, [
-        'type' => 'uri_link',
-      ])
-      ->save();
   }
 
 }