diff --git a/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php b/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
index 026b0e5c21..160d9c65ea 100644
--- a/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
+++ b/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
@@ -18,7 +18,7 @@ class UnpublishedBlockTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * Tests unpublishing of block_content entities.
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php
index 57d6177922..40186c231e 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ContactFormHalJsonAnonTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php
index 9aec186e15..8a426f702b 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ContactFormHalJsonBasicAuthTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php
index 0d78991f95..14ddba586a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ContactFormHalJsonCookieTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php
index 9e6bcb3065..d0f06fe630 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php
@@ -17,7 +17,7 @@ class EntityTestBundleHalJsonAnonTest extends EntityTestBundleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php
index 09e5970890..400b48a926 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class EntityTestBundleHalJsonBasicAuthTest extends EntityTestBundleResourceTestB
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php
index 7f499fa016..76ea300b66 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityTestBundleHalJsonCookieTest extends EntityTestBundleResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php
index c41b9a4ef4..d54dcf8f0f 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ContactFormJsonBasicAuthTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php
index 51e297a7b8..cbad9541fa 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php
index 0220801379..a902d7ca5d 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityTestBundleJsonBasicAuthTest extends EntityTestBundleResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php
index f43d877097..ee6638bc25 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php b/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php
index 3f9cc87be3..94d78fa052 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'toolbar', 'shortcut'];
+  protected static $modules = ['node', 'toolbar', 'shortcut'];
 
   /**
    * User with permission to administer shortcuts.