diff --git a/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
index ccfe1baa4635..e913bcf688f8 100644
--- a/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
@@ -52,7 +52,7 @@ abstract class LocaleUpdateBase extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
 
     // Setup timestamps to identify old and new translation sources.
diff --git a/core/modules/media/tests/src/Functional/MediaFunctionalTestTrait.php b/core/modules/media/tests/src/Functional/MediaFunctionalTestTrait.php
index 702518dac35a..379ba7471791 100644
--- a/core/modules/media/tests/src/Functional/MediaFunctionalTestTrait.php
+++ b/core/modules/media/tests/src/Functional/MediaFunctionalTestTrait.php
@@ -56,7 +56,7 @@ trait MediaFunctionalTestTrait {
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
 
     // Have two users ready to be used in tests.
diff --git a/core/modules/media/tests/src/FunctionalJavascript/MediaSourceTestBase.php b/core/modules/media/tests/src/FunctionalJavascript/MediaSourceTestBase.php
index 96dbfcbe5f7c..8b28129c4f02 100644
--- a/core/modules/media/tests/src/FunctionalJavascript/MediaSourceTestBase.php
+++ b/core/modules/media/tests/src/FunctionalJavascript/MediaSourceTestBase.php
@@ -14,7 +14,7 @@ abstract class MediaSourceTestBase extends MediaJavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
 
     // Let's set the canonical flag in the base class of the source tests,
diff --git a/core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php b/core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php
index 2a569025dad3..1932433330f3 100644
--- a/core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php
+++ b/core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php
@@ -24,7 +24,7 @@ abstract class MigrateProcessTestCase extends MigrateTestCase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     $this->row = $this->getMockBuilder('Drupal\migrate\Row')
       ->disableOriginalConstructor()
       ->getMock();
diff --git a/core/modules/migrate/tests/src/Unit/process/MigrationLookupTestCase.php b/core/modules/migrate/tests/src/Unit/process/MigrationLookupTestCase.php
index f23883aa8cec..c22127dd9d8f 100644
--- a/core/modules/migrate/tests/src/Unit/process/MigrationLookupTestCase.php
+++ b/core/modules/migrate/tests/src/Unit/process/MigrationLookupTestCase.php
@@ -28,7 +28,7 @@ abstract class MigrationLookupTestCase extends MigrateProcessTestCase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
     $this->migrateStub = $this->prophesize(MigrateStub::class);
     $this->migrateLookup = $this->prophesize(MigrateLookupInterface::class);
diff --git a/core/modules/tour/tests/src/Functional/TourTestBasic.php b/core/modules/tour/tests/src/Functional/TourTestBasic.php
index f0c9240bd574..2f4d9674dc8b 100644
--- a/core/modules/tour/tests/src/Functional/TourTestBasic.php
+++ b/core/modules/tour/tests/src/Functional/TourTestBasic.php
@@ -39,7 +39,7 @@ abstract class TourTestBasic extends TourTestBase {
    */
   protected $permissions = ['access tour'];
 
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
 
     // Make sure we are using distinct default and administrative themes for
diff --git a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php
index 166ad9b57fdd..cd68de55a3a3 100644
--- a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php
+++ b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php
@@ -37,7 +37,7 @@ abstract class MTimeProtectedFileStorageBase extends PhpStorageTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
 
     // Random generator.