diff --git a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraint.php b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraint.php
index e2a0a5f..beaff89 100644
--- a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraint.php
+++ b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraint.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Validation\Plugin\Validation\Constraint;
 
-use Symfony\Component\Validator\Constraints\Null;
+use Symfony\Component\Validator\Constraints\IsNull;
 
 /**
  * Null constraint.
@@ -20,4 +20,4 @@
  *   type = false
  * )
  */
-class NullConstraint extends Null { }
+class NullConstraint extends IsNull { }
diff --git a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraintValidator.php b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraintValidator.php
index b584687..13efea2 100644
--- a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraintValidator.php
+++ b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NullConstraintValidator.php
@@ -11,14 +11,14 @@
 use Drupal\Core\TypedData\ListInterface;
 use Drupal\Core\TypedData\Validation\TypedDataAwareValidatorTrait;
 use Symfony\Component\Validator\Constraint;
-use Symfony\Component\Validator\Constraints\NullValidator;
+use Symfony\Component\Validator\Constraints\IsNullValidator;
 
 /**
  * Null constraint validator.
  *
  * Overrides the symfony validator to handle empty Typed Data structures.
  */
-class NullConstraintValidator extends NullValidator {
+class NullConstraintValidator extends IsNullValidator {
 
   use TypedDataAwareValidatorTrait;