diff --git a/tests/src/Functional/BasicTest.php b/tests/src/Functional/BasicTest.php
index aa0b76e..05d0153 100644
--- a/tests/src/Functional/BasicTest.php
+++ b/tests/src/Functional/BasicTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\entity_reference_tree\Functional;
 
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\RunTestsInSeparateProcesses;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
@@ -12,6 +14,8 @@ use Drupal\Tests\BrowserTestBase;
  *
  * @group entity_reference_tree
  */
+#[Group('entity_reference_tree')]
+#[RunTestsInSeparateProcesses]
 class BasicTest extends BrowserTestBase {
 
   /**
diff --git a/tests/src/FunctionalJavascript/BasicJavascriptTest.php b/tests/src/FunctionalJavascript/BasicJavascriptTest.php
index 65affd9..3bea062 100644
--- a/tests/src/FunctionalJavascript/BasicJavascriptTest.php
+++ b/tests/src/FunctionalJavascript/BasicJavascriptTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\entity_reference_tree\FunctionalJavascript;
 
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\RunTestsInSeparateProcesses;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
@@ -12,6 +14,8 @@ use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
  *
  * @group entity_reference_tree
  */
+#[Group('entity_reference_tree')]
+#[RunTestsInSeparateProcesses]
 class BasicJavascriptTest extends WebDriverTestBase {
 
   /**