diff --git a/core/modules/field_ui/tests/src/Functional/ManageFieldsLifecycleTest.php b/core/modules/field_ui/tests/src/Functional/ManageFieldsLifecycleTest.php
index 5d80b3c28ef227e3bdbc8a77fa6b8e0a0734f56c..faea205ff07970958567f929a8b07e0b798996be 100644
--- a/core/modules/field_ui/tests/src/Functional/ManageFieldsLifecycleTest.php
+++ b/core/modules/field_ui/tests/src/Functional/ManageFieldsLifecycleTest.php
@@ -292,7 +292,7 @@ protected function addPersistentFieldStorage(): void {
     $this->assertSession()->pageTextContains('Re-use an existing field');
 
     // Ensure that we test with a label that contains HTML.
-    $label = $this->randomString(4) . '<br/>' . $this->randomString(4);
+    $label = $this->randomMachineName(4) . '<br/>' . $this->randomMachineName(4);
     // Add a new field for the orphaned storage.
     $this->fieldUIAddExistingField("admin/structure/types/manage/page", $this->fieldName, $label);
   }
diff --git a/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php b/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php
index 707b4b65b7bae3a3067689f692ec103dce870dfd..271bb31b08161d3ccffeded377adceea6006b24f 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php
@@ -53,7 +53,7 @@ protected function setUp(): void {
    */
   public function testNodeAccessMenuLink(): void {
 
-    $menu_link_title = $this->randomString();
+    $menu_link_title = 'Test menu link title';
 
     $this->drupalLogin($this->contentAdminUser);
     $edit = [
diff --git a/core/modules/system/tests/src/Functional/System/TrustedHostsTest.php b/core/modules/system/tests/src/Functional/System/TrustedHostsTest.php
index a1ae5b761076f62603a50baa0bb3f40a888d3554..7cc42e14c3db96d6aee793cc9ff5f6fa4051ae9d 100644
--- a/core/modules/system/tests/src/Functional/System/TrustedHostsTest.php
+++ b/core/modules/system/tests/src/Functional/System/TrustedHostsTest.php
@@ -94,7 +94,7 @@ public function testShortcut(): void {
     $shortcut_storage = $entity_type_manager->getStorage('shortcut');
 
     $shortcut = $shortcut_storage->create([
-      'title' => $this->randomString(),
+      'title' => 'Test Shortcut Label',
       'link' => 'internal:/admin/reports/status',
       'shortcut_set' => 'default',
     ]);
diff --git a/core/modules/views/tests/src/Functional/Entity/EntityQueryAccessTest.php b/core/modules/views/tests/src/Functional/Entity/EntityQueryAccessTest.php
index 1a5b85353ae19cddf04a78ab8e4593b711b4032e..eba3696288f738d791c218cafcf61888dec4a210 100644
--- a/core/modules/views/tests/src/Functional/Entity/EntityQueryAccessTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/EntityQueryAccessTest.php
@@ -49,14 +49,14 @@ public function testMediaEntityQueryAccess(): void {
       // view.
       // @see views_test_access_query_media_access_alter()
       'uuid' => 'hidden-media',
-      'name' => $this->randomString(),
+      'name' => 'Test hidden media title',
       $source_field => $this->randomString(),
     ]);
     $hidden_media->save();
 
     $accessible_media = Media::create([
       'bundle' => $media_type->id(),
-      'name' => $this->randomString(),
+      'name' => 'Test accessible media title',
       $source_field => $this->randomString(),
     ]);
     $accessible_media->save();
diff --git a/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php b/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
index 7b5b1a8fd7b9cf5801d7f1595681f86376ea08cb..8af887d1ef1ba65f34b684e4aaa4b9bb12f858a3 100644
--- a/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
@@ -147,7 +147,7 @@ public function testDisplayPlugin(): void {
 
     $this->clickLink('Test option title');
 
-    $test_option = $this->randomString();
+    $test_option = $this->randomMachineName();
     $this->submitForm(['test_option' => $test_option], 'Apply');
 
     // Check the new value has been saved by checking the UI summary text.