diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/ChangedItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/ChangedItem.php
index b93ac7a..ee9e632 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/ChangedItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/ChangedItem.php
@@ -16,7 +16,7 @@
  *   description = @Translation("An entity field containing a UNIX timestamp of when the entity has been last updated."),
  *   configurable = FALSE,
  *   constraints = {
- *     "ComplexData" = {"value" = {"EntityChanged" = TRUE}}
+ *     "ComplexData" = {"value" = {"EntityChanged" = {}}}
  *   }
  * )
  */
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
index 655f4fd..3b2bfa3 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -24,7 +24,7 @@
  *   label = @Translation("Entity reference"),
  *   description = @Translation("An entity field containing an entity reference."),
  *   configurable = FALSE,
- *   constraints = {"ValidReference" = TRUE}
+ *   constraints = {"ValidReference" = {}}
  * )
  */
 class EntityReferenceItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/TypedData/Plugin/DataType/Email.php b/core/lib/Drupal/Core/TypedData/Plugin/DataType/Email.php
index f68ffc2..91740e5 100644
--- a/core/lib/Drupal/Core/TypedData/Plugin/DataType/Email.php
+++ b/core/lib/Drupal/Core/TypedData/Plugin/DataType/Email.php
@@ -17,7 +17,7 @@
  * @DataType(
  *   id = "email",
  *   label = @Translation("Email"),
- *   constraints = {"Email" = TRUE}
+ *   constraints = {"Email" = {}}
  * )
  */
 class Email extends String implements StringInterface {
diff --git a/core/lib/Drupal/Core/Validation/ConstraintManager.php b/core/lib/Drupal/Core/Validation/ConstraintManager.php
index 093fb21..12bbf11 100644
--- a/core/lib/Drupal/Core/Validation/ConstraintManager.php
+++ b/core/lib/Drupal/Core/Validation/ConstraintManager.php
@@ -66,8 +66,7 @@ public function __construct(\Traversable $namespaces, CacheBackendInterface $cac
    *   A validation constraint plugin.
    */
   public function create($name, $options) {
-    // Annotations do not support empty arrays, so support specifying TRUE also.
-    if ($options === TRUE || !isset($options)) {
+    if (!isset($options)) {
       $options = array();
     }
     elseif (!is_array($options)) {
diff --git a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/PrimitiveTypeConstraintValidator.php b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/PrimitiveTypeConstraintValidator.php
index 6ed2d3a..fe3a1fb 100644
--- a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/PrimitiveTypeConstraintValidator.php
+++ b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/PrimitiveTypeConstraintValidator.php
@@ -54,10 +54,10 @@ public function validate($value, Constraint $constraint) {
     }
     // @todo: Move those to separate constraint validators.
     try {
-      if ($typed_data instanceof DateTimeInterface && $typed_data->getDateTime()->hasErrors()) {
+      if ($typed_data instanceof DateTimeInterface && $typed_data->getDateTime() && $typed_data->getDateTime()->hasErrors()) {
         $valid = FALSE;
       }
-      if ($typed_data instanceof DurationInterface && !($typed_data->getDuration() instanceof \DateInterval)) {
+      if ($typed_data instanceof DurationInterface && $typed_data->getDuration() && !($typed_data->getDuration() instanceof \DateInterval)) {
         $valid = FALSE;
       }
     }