diff --git a/tests/src/Functional/EmailedExportFileDownloadAccessTest.php b/tests/src/Functional/EmailedExportFileDownloadAccessTest.php
index 575ec33..b2b5f29 100644
--- a/tests/src/Functional/EmailedExportFileDownloadAccessTest.php
+++ b/tests/src/Functional/EmailedExportFileDownloadAccessTest.php
@@ -14,6 +14,11 @@ use Drupal\webform_scheduled_tasks\Plugin\WebformScheduledTasks\Task\EmailedExpo
  */
 class EmailedExportFileDownloadAccessTest extends BrowserTestBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * Modules to enable.
    *
diff --git a/tests/src/Functional/ScheduledTaskAdminFormTest.php b/tests/src/Functional/ScheduledTaskAdminFormTest.php
index ebbb3e1..5c80aad 100644
--- a/tests/src/Functional/ScheduledTaskAdminFormTest.php
+++ b/tests/src/Functional/ScheduledTaskAdminFormTest.php
@@ -12,6 +12,11 @@ use Drupal\webform_scheduled_tasks\Entity\WebformScheduledTask;
  */
 class ScheduledTaskAdminFormTest extends BrowserTestBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * Modules to enable.
    *
diff --git a/tests/src/Functional/ScheduledTaskListBuilderTest.php b/tests/src/Functional/ScheduledTaskListBuilderTest.php
index a2a032b..dc5f8e9 100644
--- a/tests/src/Functional/ScheduledTaskListBuilderTest.php
+++ b/tests/src/Functional/ScheduledTaskListBuilderTest.php
@@ -13,6 +13,11 @@ use Drupal\webform_scheduled_tasks\Entity\WebformScheduledTask;
  */
 class ScheduledTaskListBuilderTest extends BrowserTestBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * Modules to enable.
    *
diff --git a/tests/src/Functional/ScheduledTaskRunTest.php b/tests/src/Functional/ScheduledTaskRunTest.php
index 93a5e57..df83701 100644
--- a/tests/src/Functional/ScheduledTaskRunTest.php
+++ b/tests/src/Functional/ScheduledTaskRunTest.php
@@ -14,6 +14,11 @@ class ScheduledTaskRunTest extends BrowserTestBase {
 
   use CronRunTrait;
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * Modules to enable.
    *
diff --git a/tests/src/FunctionalJavascript/EmailedExportUiTest.php b/tests/src/FunctionalJavascript/EmailedExportUiTest.php
index 3664f5a..4b2acc8 100644
--- a/tests/src/FunctionalJavascript/EmailedExportUiTest.php
+++ b/tests/src/FunctionalJavascript/EmailedExportUiTest.php
@@ -12,6 +12,11 @@ use Drupal\webform_scheduled_tasks\Entity\WebformScheduledTask;
  */
 class EmailedExportUiTest extends WebDriverTestBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * Modules to enable.
    *
diff --git a/tests/src/Kernel/HaltedTasksHealthzTest.php b/tests/src/Kernel/HaltedTasksHealthzTest.php
index 99cd596..50c8eed 100644
--- a/tests/src/Kernel/HaltedTasksHealthzTest.php
+++ b/tests/src/Kernel/HaltedTasksHealthzTest.php
@@ -43,6 +43,7 @@ class HaltedTasksHealthzTest extends KernelTestBase {
    */
   public function testHealthCheck() {
     $webform = Webform::create(['id' => 'foo']);
+    $webform->save();
     $schedule = WebformScheduledTask::create([
       'id' => 'foo',
       'result_set_type' => 'all_submissions',
diff --git a/tests/src/Kernel/ScheduleHaltResumeTest.php b/tests/src/Kernel/ScheduleHaltResumeTest.php
index 2627eaf..38cce62 100644
--- a/tests/src/Kernel/ScheduleHaltResumeTest.php
+++ b/tests/src/Kernel/ScheduleHaltResumeTest.php
@@ -42,6 +42,7 @@ class ScheduleHaltResumeTest extends KernelTestBase {
    */
   public function testHaltResume() {
     $webform = Webform::create(['id' => 'foo']);
+    $webform->save();
     $schedule = WebformScheduledTask::create([
       'id' => 'foo',
       'result_set_type' => 'all_submissions',
diff --git a/tests/src/Kernel/ScheduleIntervalTest.php b/tests/src/Kernel/ScheduleIntervalTest.php
index fb2b3d2..f7ae3b3 100644
--- a/tests/src/Kernel/ScheduleIntervalTest.php
+++ b/tests/src/Kernel/ScheduleIntervalTest.php
@@ -48,7 +48,7 @@ class ScheduleIntervalTest extends KernelTestBase {
    * @dataProvider scheduleIntervalsTestCases
    */
   public function testScheduleIntervals($entity_values, $expected_next_run) {
-    Webform::create(['id' => 'foo']);
+    Webform::create(['id' => 'foo'])->save();
     $scheduled_task = WebformScheduledTask::create([
       'id' => 'foo',
       'result_set_type' => 'all_submissions',
@@ -104,7 +104,7 @@ class ScheduleIntervalTest extends KernelTestBase {
    * Test manually setting an interval date.
    */
   public function testManuallySetIntervalDate() {
-    Webform::create(['id' => 'foo']);
+    Webform::create(['id' => 'foo'])->save();
     $scheduled_task = WebformScheduledTask::create([
       'id' => 'foo',
       'result_set_type' => 'all_submissions',
diff --git a/tests/src/Kernel/WebformScheduledTaskDependenciesTest.php b/tests/src/Kernel/WebformScheduledTaskDependenciesTest.php
index 188d5f1..a4d1e38 100644
--- a/tests/src/Kernel/WebformScheduledTaskDependenciesTest.php
+++ b/tests/src/Kernel/WebformScheduledTaskDependenciesTest.php
@@ -34,6 +34,7 @@ class WebformScheduledTaskDependenciesTest extends KernelTestBase {
     parent::setUp();
 
     $this->installSchema('webform', ['webform']);
+    $this->installSchema('user', ['users_data']);
     $this->installEntitySchema('webform_submission');
     $this->installEntitySchema('user');
   }
diff --git a/tests/src/Kernel/WebformScheduledTaskSerializationTest.php b/tests/src/Kernel/WebformScheduledTaskSerializationTest.php
index 173fabc..c971bc9 100644
--- a/tests/src/Kernel/WebformScheduledTaskSerializationTest.php
+++ b/tests/src/Kernel/WebformScheduledTaskSerializationTest.php
@@ -41,7 +41,7 @@ class WebformScheduledTaskSerializationTest extends KernelTestBase {
    * Test serializing the entity.
    */
   public function testSerialize() {
-    Webform::create(['id' => 'foo']);
+    Webform::create(['id' => 'foo'])->save();
     $scheduled_task = WebformScheduledTask::create([
       'id' => 'foo',
       'result_set_type' => 'all_submissions',
diff --git a/webform_scheduled_tasks.info.yml b/webform_scheduled_tasks.info.yml
index 6558260..4bad1b2 100644
--- a/webform_scheduled_tasks.info.yml
+++ b/webform_scheduled_tasks.info.yml
@@ -7,3 +7,4 @@ dependencies:
   - drupal:file
 test_dependencies:
   - healthz:healthz
+  - webform:webform (>=6.x)