diff --git a/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php b/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php
index 1a52527..8ffcd29 100644
--- a/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php
+++ b/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php
@@ -265,6 +265,11 @@ public function testLoadAllIncludes() {
 
   /**
    * @covers ::loadInclude
+   *
+   * Note we load code, so isolate the test.
+   *
+   * @runTestsInSeparateProcesses
+   * @preserveGlobalState disabled
    */
   public function testLoadInclude() {
     // Include exists.
diff --git a/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php b/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php
index 5de6780..5ef5ecf 100644
--- a/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php
+++ b/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php
@@ -17,9 +17,10 @@
  * @coversDefaultClass \Drupal\Core\Update\UpdateRegistry
  * @group Update
  *
- * Note we load code, so we should better run in isolation.
+ * Note we load code, so isolate the tests.
  *
  * @runTestsInSeparateProcesses
+ * @preserveGlobalState disabled
  */
 class UpdateRegistryTest extends UnitTestCase {