diff --git a/core/modules/user/tests/src/Unit/Plugin/Validation/Constraint/ProtectedUserFieldConstraintValidatorTest.php b/core/modules/user/tests/src/Unit/Plugin/Validation/Constraint/ProtectedUserFieldConstraintValidatorTest.php
index d05ac030e919bf562396e5bef1df4e024bd44f93..6a6e9f0ec33e84d797dc782b417ebe04c9709602 100644
--- a/core/modules/user/tests/src/Unit/Plugin/Validation/Constraint/ProtectedUserFieldConstraintValidatorTest.php
+++ b/core/modules/user/tests/src/Unit/Plugin/Validation/Constraint/ProtectedUserFieldConstraintValidatorTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\user\Unit\Plugin\Validation\Constraint;
 
 use Drupal\Tests\UnitTestCase;
+use Drupal\user\Entity\User;
 use Drupal\user\Plugin\Validation\Constraint\ProtectedUserFieldConstraint;
 use Drupal\user\Plugin\Validation\Constraint\ProtectedUserFieldConstraintValidator;
 use Symfony\Component\Validator\Context\ExecutionContextInterface;
@@ -87,7 +88,7 @@ public function providerTestValidate() {
 
     // Case 3: Account flagged to skip protected user should be ignored.
     $field_definition = $this->createMock('Drupal\Core\Field\FieldDefinitionInterface');
-    $account = $this->createMock('Drupal\user\UserInterface');
+    $account = $this->createMock(User::class);
     $account->_skipProtectedUserFieldConstraint = TRUE;
     $items = $this->createMock('Drupal\Core\Field\FieldItemListInterface');
     $items->expects($this->once())