diff --git a/src/Form/ConfigSplitEntityForm.php b/src/Form/ConfigSplitEntityForm.php
index d0f1ec0dc228a34aace9a838e218c2d2b2e9326a..649370af2ce16f03a41fbd86a6d5cd04792a7564 100644
--- a/src/Form/ConfigSplitEntityForm.php
+++ b/src/Form/ConfigSplitEntityForm.php
@@ -4,6 +4,8 @@
 
 use Drupal\config_split\Config\StatusOverride;
 use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Extension\ModuleExtensionList;
+use Drupal\Core\Extension\ThemeExtensionList;
 use Drupal\Core\Extension\ThemeHandlerInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Site\Settings;
@@ -30,11 +32,18 @@ class ConfigSplitEntityForm extends EntityForm {
   protected $state;
 
   /**
-   * Drupal\Core\Extension\ThemeHandler definition.
+   * The module list.
    *
-   * @var \Drupal\Core\Extension\ThemeHandlerInterface
+   * @var \Drupal\Core\Extension\ModuleExtensionList
    */
-  protected $themeHandler;
+  protected $moduleExtensionList;
+
+  /**
+   * The theme list.
+   *
+   * @var \Drupal\Core\Extension\ThemeExtensionList
+   */
+  protected $themeExtensionList;
 
   /**
    * The entity being used by this form.
@@ -50,17 +59,21 @@ class ConfigSplitEntityForm extends EntityForm {
    *   The split status override service.
    * @param \Drupal\Core\State\StateInterface $state
    *   The drupal state.
-   * @param \Drupal\Core\Extension\ThemeHandlerInterface $themeHandler
-   *   The theme handler.
+   * @param \Drupal\Core\Extension\ModuleExtensionList $moduleExtensionList
+   *   The module list.
+   * @param \Drupal\Core\Extension\ThemeExtensionList $themeExtensionList
+   *   The theme list.
    */
   public function __construct(
     StatusOverride $statusOverride,
     StateInterface $state,
-    ThemeHandlerInterface $themeHandler
+    ModuleExtensionList $moduleExtensionList,
+    ThemeExtensionList $themeExtensionList,
   ) {
     $this->statusOverride = $statusOverride;
     $this->state = $state;
-    $this->themeHandler = $themeHandler;
+    $this->moduleExtensionList = $moduleExtensionList;
+    $this->themeExtensionList = $themeExtensionList;
   }
 
   /**
@@ -70,7 +83,8 @@ public static function create(ContainerInterface $container) {
     return new static(
       $container->get('config_split.status_override'),
       $container->get('state'),
-      $container->get('theme_handler')
+      $container->get('extension.list.module'),
+      $container->get('extension.list.theme'),
     );
   }
 
@@ -184,10 +198,10 @@ public function form(array $form, FormStateInterface $form_state) {
        recorded in a config patch saved in in the split storage."),
     ];
 
-    $module_handler = $this->moduleHandler;
+    $module_handler = $this->moduleExtensionList;
     $modules = array_map(function ($module) use ($module_handler) {
       return $module_handler->getName($module->getName());
-    }, $module_handler->getModuleList());
+    }, $module_handler->getList());
     // Add the existing ones with the machine name, so they do not get lost.
     foreach (array_diff_key($config->get('module'), $modules) as $missing => $weight) {
       $modules[$missing] = $missing;
@@ -214,10 +228,10 @@ public function form(array $form, FormStateInterface $form_state) {
     ];
 
     // We should probably find a better way for this.
-    $theme_handler = $this->themeHandler;
+    $theme_handler = $this->themeExtensionList;
     $themes = array_map(function ($theme) use ($theme_handler) {
       return $theme_handler->getName($theme->getName());
-    }, $theme_handler->listInfo());
+    }, $theme_handler->getList());
     $form['complete_fieldset']['theme'] = [
       '#type' => $multiselect_type,
       '#title' => $this->t('Themes'),
diff --git a/tests/src/Kernel/NoPatchSplitMergeTest.php b/tests/src/Kernel/NoPatchSplitMergeTest.php
index e1f0cee66850c3fa547befe3e5e0325d10403919..c5fcf279c533b92bc92b88800243530c438be4b0 100644
--- a/tests/src/Kernel/NoPatchSplitMergeTest.php
+++ b/tests/src/Kernel/NoPatchSplitMergeTest.php
@@ -68,7 +68,7 @@ protected function setUp(): void {
    * @return string[][]
    *   The different storage types.
    */
-  public function storageAlternativesProvider(): array {
+  public static function storageAlternativesProvider(): array {
     return [['folder'], ['collection'], ['database']];
   }
 
diff --git a/tests/src/Kernel/PatchSequenceTest.php b/tests/src/Kernel/PatchSequenceTest.php
index 02fc5d5fb311295e91820c0d3a384569cce85530..0313b2dcb17b2878098e9b82f63044d93970a8dd 100644
--- a/tests/src/Kernel/PatchSequenceTest.php
+++ b/tests/src/Kernel/PatchSequenceTest.php
@@ -75,7 +75,7 @@ public function testSequencePatch(string $name, array $configA, array $configB,
   /**
    * Data provider for complex examples with a real schema.
    */
-  public function sequenceProvider() {
+  public static function sequenceProvider() {
     $a = [
       'nested' => [
         [
diff --git a/tests/src/Kernel/RolesSplittingTest.php b/tests/src/Kernel/RolesSplittingTest.php
index 9cfdc8c441268e075fcdd21d48caeb1ac3e33c46..1dcb1afd091890f661e58c79fded687c0de020ab 100644
--- a/tests/src/Kernel/RolesSplittingTest.php
+++ b/tests/src/Kernel/RolesSplittingTest.php
@@ -121,10 +121,10 @@ public function testRoleSplit() {
   }
 
   /**
-   * Test splitting a role into multiple "feature-splits"
+   * Test splitting a role into multiple "feature-splits".
    */
   public function testRoleMultiSplit() {
-    // We use shortcut and block to create the "feature-splits"
+    // We use shortcut and block to create the "feature-splits".
     $this->enableModules(['shortcut', 'block']);
 
     // Create a role with permissions from both modules.
@@ -180,7 +180,6 @@ public function testRoleMultiSplit() {
       'removing' => [],
     ]);
 
-
     foreach (['feature_shortcut','feature_block'] as $id) {
       // Check if the split actually has the expected configs.
       $patch = $storage->createCollection('split.'.$id)->read('config_split.patch.user.role.test_role');
diff --git a/tests/src/Kernel/SplitContentEntityTypeTest.php b/tests/src/Kernel/SplitContentEntityTypeTest.php
index c51da6cfe9e851487df87998630f1373f5e078f2..256bff5b051612586ac6fb37ad5aa26cf7653794 100644
--- a/tests/src/Kernel/SplitContentEntityTypeTest.php
+++ b/tests/src/Kernel/SplitContentEntityTypeTest.php
@@ -100,7 +100,7 @@ protected function setUp(): void {
    * @return string[][]
    *   The different storage types.
    */
-  public function storageAlternativesProvider(): array {
+  public static function storageAlternativesProvider(): array {
     return [['folder'], ['collection'], ['database']];
   }
 
diff --git a/tests/src/Kernel/SplitMergeTest.php b/tests/src/Kernel/SplitMergeTest.php
index dfe073d9dd33f47d6ecb0ed348d6200a27add230..22184eda48b1d0e9f9827be346353034a0e24338 100644
--- a/tests/src/Kernel/SplitMergeTest.php
+++ b/tests/src/Kernel/SplitMergeTest.php
@@ -69,7 +69,7 @@ protected function setUp(): void {
    * @return string[][]
    *   The different storage types.
    */
-  public function storageAlternativesProvider(): array {
+  public static function storageAlternativesProvider(): array {
     return [['folder'], ['collection'], ['database']];
   }
 
diff --git a/tests/src/Kernel/SplitTestTrait.php b/tests/src/Kernel/SplitTestTrait.php
index 43e10de56bd5089996cbf3f95d8a56317a5aabfe..77be06d36f98a8da7f78d7eabcf06adb088b2641 100644
--- a/tests/src/Kernel/SplitTestTrait.php
+++ b/tests/src/Kernel/SplitTestTrait.php
@@ -179,7 +179,8 @@ protected function validateImport(StorageInterface $storage): void {
       $container->get('module_installer'),
       $container->get('theme_handler'),
       $container->get('string_translation'),
-      $container->get('extension.list.module')
+      $container->get('extension.list.module'),
+      $container->get('extension.list.theme'),
     );
 
     $importer->validate();
diff --git a/tests/src/Unit/ConfigPatchTest.php b/tests/src/Unit/ConfigPatchTest.php
index 79221042fcb9d7af24682ba2ae2477c14ec006bf..68fea806c24906577deabda1f7272e443ff9f0f1 100644
--- a/tests/src/Unit/ConfigPatchTest.php
+++ b/tests/src/Unit/ConfigPatchTest.php
@@ -90,7 +90,7 @@ public function testStandardPatchMerge(array $configA, array $configB, ConfigPat
    * @return \Generator
    *   The test cases.
    */
-  public function standardPatchMergeProvider() {
+  public static function standardPatchMergeProvider() {
     yield 'deep merge' => [
       'configA' => [
         'dependencies' => ['a', 'b'],