diff --git a/fivestar.info.yml b/fivestar.info.yml
index 38a88d7..dd6f2c0 100644
--- a/fivestar.info.yml
+++ b/fivestar.info.yml
@@ -2,7 +2,7 @@ name: Fivestar
 type: module
 description: 'Enables fivestar ratings on content, users, etc.'
 package: Voting
-core_version_requirement: ^8.8.2 || ^9
+core_version_requirement: ^8.8.2 || ^9 || ^10
 dependencies:
   - votingapi:votingapi
 
diff --git a/fivestar.libraries.yml b/fivestar.libraries.yml
index 1e829b7..90123d1 100644
--- a/fivestar.libraries.yml
+++ b/fivestar.libraries.yml
@@ -7,9 +7,9 @@ fivestar.base:
     js/fivestar.js: {}
 
   dependencies:
-    - core/jquery
     - core/drupal
-    - core/jquery.once
+    - core/jquery
+    - core/once
     - core/drupal.ajax
 
 fivestar.admin:
@@ -18,15 +18,6 @@ fivestar.admin:
     component:
       css/fivestar-admin.css: {}
 
-fivestar.ajax:
-  version: VERSION
-  js:
-    js/fivestar.ajax.js: {}
-  dependencies:
-    - core/jquery
-    - core/drupal
-    - core/jquery.once
-
 # Widgets
 # Right now does not include RTL handling
 basic:
diff --git a/js/fivestar.js b/js/fivestar.js
index c1b7ac1..973e229 100644
--- a/js/fivestar.js
+++ b/js/fivestar.js
@@ -20,7 +20,7 @@
         }
       });
 
-      $(context).find('div.fivestar-form-item').once('fivestar').each(function() {
+      $(once('fivestar', 'div.fivestar-form-item', context)).each(function() {
         var $cancel, $container, $options, $select, $this, index;
         $this = $(this);
         $container = $('<div class="fivestar-widget clearfix"></div>');
@@ -89,21 +89,4 @@
       }
     }
   };
-})(jQuery);
-
-
-/**
- * @file
- *
- * Fivestar AJAX for updating fivestar widgets.
- */
-
-/**
- * Create a degradeable star rating interface out of a simple form structure.
- */
-(function($) {
-  Drupal.AjaxCommands.prototype.fivestarUpdate = function(ajax, response, status) {
-    response.selector = $('.fivestar-form-item', ajax.element.form);
-    ajax.commands.insert(ajax, response, status);
-  };
-})(jQuery);
+})(jQuery, once);
diff --git a/test/fivestar.base.test b/test/fivestar.base.test
index 95cee23..33ad2d9 100644
--- a/test/fivestar.base.test
+++ b/test/fivestar.base.test
@@ -24,7 +24,7 @@ class FivestarBaseTestCase extends AJAXTestCase {
   /**
    *
    */
-  public function setUp() {
+  public function setUp(): void {
     parent::setUp(['fivestar', 'dblog']);
 
     $type = $this->drupalCreateContentType(['type' => 'test_node_type', 'name' => 'test_node_type']);
@@ -38,7 +38,7 @@ class FivestarBaseTestCase extends AJAXTestCase {
    * @param $options
    *   An associative array of options for the field and instance.
    */
-  public function createFivestarField($options = []) {
+  public function createFivestarField($options = []): void {
     $options = $options + [
       'content_type' => 'test_node_type',
       'widget_type' => 'stars',
diff --git a/test/fivestar.field.test b/test/fivestar.field.test
index 547b107..91d3a66 100644
--- a/test/fivestar.field.test
+++ b/test/fivestar.field.test
@@ -13,7 +13,7 @@ class FivestarTestCase extends FivestarBaseTestCase {
   /**
    *
    */
-  public static function getInfo() {
+  public static function getInfo(): array {
     return [
       'name' => 'Fivestar widgets',
       'description' => 'Make sure fivestar widgets can be created and used.',
@@ -24,7 +24,7 @@ class FivestarTestCase extends FivestarBaseTestCase {
   /**
    * Test that users can rate content with exposed widgets.
    */
-  public function testViewerRating() {
+  public function testViewerRating(): void {
     $this->createFivestarField(['widget_type' => 'exposed']);
     // Add an test_node_type to rate.
     $node = $this->drupalCreateNode(['type' => 'test_node_type']);
@@ -71,7 +71,7 @@ class FivestarTestCase extends FivestarBaseTestCase {
   /**
    * Test that users can rate content with exposed widgets.
    */
-  public function testViewerRatingAjax() {
+  public function testViewerRatingAjax(): void {
     // Add a viewer-rated fivestar field to the test_node_type content type.
     $this->createFivestarField(['widget_type' => 'exposed']);
     // Add an test_node_type to rate.
@@ -94,7 +94,7 @@ class FivestarTestCase extends FivestarBaseTestCase {
    * Test that we can switch the fivestar widgets around for the exposed
    * widget type.
    */
-  public function testExposedWidgetDisplay() {
+  public function testExposedWidgetDisplay(): void {
     // Lets add an exposed widget but display the static widget.
     // It's simpler to compare the display type using the static widget.
     $this->createFivestarField([
diff --git a/tests/src/Functional/FivestarTest.php b/tests/src/Functional/FivestarTest.php
index 7f69f0b..4bf4765 100644
--- a/tests/src/Functional/FivestarTest.php
+++ b/tests/src/Functional/FivestarTest.php
@@ -22,7 +22,7 @@ class FivestarTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  protected $defaultTheme = 'classy';
+  protected $defaultTheme = 'stark';
 
   /**
    * The entity display repository.
@@ -48,7 +48,7 @@ class FivestarTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
 
     // Create content type for testing.
@@ -74,7 +74,7 @@ class FivestarTest extends BrowserTestBase {
   /**
    * Tests that authors can rate their own content.
    */
-  public function testAuthorRating() {
+  public function testAuthorRating(): void {
     $this->drupalLogin($this->adminUser);
     // Add an author-rated fivestar field to the test_node_type content type.
     $this->createFivestarField([
@@ -104,7 +104,7 @@ class FivestarTest extends BrowserTestBase {
     $this->submitForm($edit, 'Save');
 
     // Make sure the two-star rating shows on the node view.
-    $elements = $this->xpath("//div[contains(@class, 'field--name-fivestar-test')]//div[contains(@class,'star-first')]/span");
+    $elements = $this->xpath("//div[contains(@class, 'fivestar-widget-static-vote')]//div[contains(@class,'star-first')]/span");
     $this->assertEquals('2', $elements[0]->getText(), 'Content authors can rate their own content using the stars widget.');
   }
 
@@ -114,7 +114,7 @@ class FivestarTest extends BrowserTestBase {
    * Tests that users cannot rate content with exposed widgets that has the
    * exposed display setting set to FALSE.
    */
-  public function testViewerNonRating() {
+  public function testViewerNonRating(): void {
     // Add an exposed field, with the 'exposed' display settings set to FALSE.
     $this->createFivestarField([
       'widget_type' => 'exposed',
@@ -142,7 +142,7 @@ class FivestarTest extends BrowserTestBase {
     // Rate the test_node_type.
     $this->drupalLogin($this->voterUser);
     $this->drupalGet('node/' . $node->id());
-    $this->assertRaw('No votes yet', 'Fivestar field has no votes.');
+    $this->assertSession()->pageTextContains('No votes yet');
     $this->assertEmpty($this->xpath("//form[contains(@class, 'fivestar-widget')]"));
 
     // Check if node with attached fivestar field can be save.
diff --git a/tests/src/FunctionalJavascript/FivestarAjaxTestBase.php b/tests/src/FunctionalJavascript/FivestarAjaxTestBase.php
index 82487e4..bf980eb 100644
--- a/tests/src/FunctionalJavascript/FivestarAjaxTestBase.php
+++ b/tests/src/FunctionalJavascript/FivestarAjaxTestBase.php
@@ -21,7 +21,7 @@ abstract class FivestarAjaxTestBase extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  protected $defaultTheme = 'classy';
+  protected $defaultTheme = 'stark';
 
   /**
    * The entity display repository.
@@ -47,7 +47,7 @@ abstract class FivestarAjaxTestBase extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
 
     // Create content type for testing.
diff --git a/tests/src/Kernel/HookFivestarWidgetsAlterTest.php b/tests/src/Kernel/HookFivestarWidgetsAlterTest.php
index 53c0c45..f2b2e04 100644
--- a/tests/src/Kernel/HookFivestarWidgetsAlterTest.php
+++ b/tests/src/Kernel/HookFivestarWidgetsAlterTest.php
@@ -30,7 +30,7 @@ class HookFivestarWidgetsAlterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
 
     $this->widgetManager = $this->container->get('fivestar.widget_manager');
@@ -39,7 +39,7 @@ class HookFivestarWidgetsAlterTest extends KernelTestBase {
   /**
    * Tests that fivestar_widget_provider_fivestar_widgets_alter() was called.
    */
-  public function testWidgetAlter() {
+  public function testWidgetAlter(): void {
     // Invoke the hook and collect all defined and altered widgets.
     $widgets = $this->widgetManager->getWidgets();
 
diff --git a/tests/src/Kernel/HookFivestarWidgetsTest.php b/tests/src/Kernel/HookFivestarWidgetsTest.php
index 88bc193..10b5578 100644
--- a/tests/src/Kernel/HookFivestarWidgetsTest.php
+++ b/tests/src/Kernel/HookFivestarWidgetsTest.php
@@ -30,7 +30,7 @@ class HookFivestarWidgetsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
 
     $this->widgetManager = $this->container->get('fivestar.widget_manager');
@@ -39,7 +39,7 @@ class HookFivestarWidgetsTest extends KernelTestBase {
   /**
    * Tests finding widgets defined by hook_fivestar_widgets().
    */
-  public function testWidgetDiscovery() {
+  public function testWidgetDiscovery(): void {
     $expected = [
       // Awesome Stars is defined in the fivestar_widget_provider module.
       'awesome' => [