diff --git a/modules/video_embed_wysiwyg/src/Form/VideoEmbedDialog.php b/modules/video_embed_wysiwyg/src/Form/VideoEmbedDialog.php
index e9cefe0..b2d80fd 100644
--- a/modules/video_embed_wysiwyg/src/Form/VideoEmbedDialog.php
+++ b/modules/video_embed_wysiwyg/src/Form/VideoEmbedDialog.php
@@ -143,7 +143,7 @@ class VideoEmbedDialog extends FormBase {
     $provider = $this->getProvider($form_state->getValue('video_url'));
     // Display an error if no provider can be loaded for this video.
     if (FALSE == $provider) {
-      $form_state->setError($form['video_url'], VideoTextfield::getProviderErrorMessage());
+      $form_state->setError($form['video_url'], $this->t('Could not find a video provider to handle the given URL.'));
       return;
     }
   }
diff --git a/src/Plugin/Field/FieldType/VideoEmbedField.php b/src/Plugin/Field/FieldType/VideoEmbedField.php
index 16867fd..3a66618 100644
--- a/src/Plugin/Field/FieldType/VideoEmbedField.php
+++ b/src/Plugin/Field/FieldType/VideoEmbedField.php
@@ -17,7 +17,8 @@ use Drupal\Core\TypedData\TraversableTypedDataInterface;
  *   description = @Translation("Stores a video and then outputs some embed code."),
  *   category = @Translation("Media"),
  *   default_widget = "video_embed_field_textfield",
- *   default_formatter = "video_embed_field_video"
+ *   default_formatter = "video_embed_field_video",
+ *   constraints = {"VideoEmbedValidation" = {}}
  * )
  */
 class VideoEmbedField extends FieldItemBase {
diff --git a/src/Plugin/Field/FieldWidget/VideoTextfield.php b/src/Plugin/Field/FieldWidget/VideoTextfield.php
index 4085902..5a5d84c 100644
--- a/src/Plugin/Field/FieldWidget/VideoTextfield.php
+++ b/src/Plugin/Field/FieldWidget/VideoTextfield.php
@@ -30,41 +30,8 @@ class VideoTextfield extends WidgetBase {
       '#maxlength' => $this->getFieldSetting('max_length'),
       '#attributes' => ['class' => ['js-text-full', 'text-full']],
       '#allowed_providers' => $this->getFieldSetting('allowed_providers'),
-      '#element_validate' => [
-          [get_class($this), 'validateFormElement'],
-      ],
     ];
     return $element;
   }
 
-  /**
-   * Form element validation handler for URL alias form element.
-   *
-   * @param array $element
-   *   The form element.
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The form state.
-   */
-  public static function validateFormElement(array &$element, FormStateInterface $form_state) {
-    $value = $element['#value'];
-    if (empty($value)) {
-      return;
-    }
-    $provider_manager = \Drupal::service('video_embed_field.provider_manager');
-    $enabled_providers = $provider_manager->loadDefinitionsFromOptionList($element['#allowed_providers']);
-    if (!$provider_manager->filterApplicableDefinitions($enabled_providers, $value)) {
-      $form_state->setError($element, static::getProviderErrorMessage());
-    }
-  }
-
-  /**
-   * Get the error message indicating a provider could not be found.
-   *
-   * @return string
-   *   The provider error message.
-   */
-  public static function getProviderErrorMessage() {
-    return t('Could not find a video provider to handle the given URL.');
-  }
-
 }
diff --git a/src/Plugin/Validation/Constraint/VideoEmbedConstraint.php b/src/Plugin/Validation/Constraint/VideoEmbedConstraint.php
new file mode 100644
index 0000000..aeef70f
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/VideoEmbedConstraint.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\video_embed_field\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Validation constraint for the video embed field.
+ *
+ * @Constraint(
+ *   id = "VideoEmbedValidation",
+ *   label = @Translation("VideoEmbed provider constraint", context = "Validation"),
+ * )
+ */
+class VideoEmbedConstraint extends Constraint {
+
+  /**
+   * Message shown when a video provider is not found.
+   *
+   * @var string
+   */
+  public $message = 'Could not find a video provider to handle the given URL.';
+
+}
diff --git a/src/Plugin/Validation/Constraint/VideoEmbedConstraintValidator.php b/src/Plugin/Validation/Constraint/VideoEmbedConstraintValidator.php
new file mode 100644
index 0000000..0d83de3
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/VideoEmbedConstraintValidator.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace Drupal\video_embed_field\Plugin\Validation\Constraint;
+
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\video_embed_field\ProviderManagerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+
+/**
+ * Validates the video embed providers.
+ */
+class VideoEmbedConstraintValidator extends ConstraintValidator implements ContainerInjectionInterface {
+
+  /**
+   * Video embed provider manager service.
+   *
+   * @var \Drupal\video_embed_field\ProviderManagerInterface
+   */
+  protected $providerManager;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('video_embed_field.provider_manager')
+    );
+  }
+
+  /**
+   * Create an instance of the validator.
+   *
+   * @param \Drupal\video_embed_field\ProviderManagerInterface $provider_manager
+   *   The provider manager service.
+   */
+  public function __construct(ProviderManagerInterface $provider_manager) {
+    $this->providerManager = $provider_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validate($field, Constraint $constraint) {
+    if (!isset($field->value)) {
+      return NULL;
+    }
+
+    $allowed_providers = $field->getFieldDefinition()->getSetting('allowed_providers');
+    $allowed_provider_definitions = $this->providerManager->loadDefinitionsFromOptionList($allowed_providers);
+
+    if (FALSE === $this->providerManager->filterApplicableDefinitions($allowed_provider_definitions, $field->value)) {
+      $this->context->addViolation($constraint->message);
+    }
+  }
+
+}
diff --git a/tests/src/Kernel/ConstraintTest.php b/tests/src/Kernel/ConstraintTest.php
new file mode 100644
index 0000000..1ed6323
--- /dev/null
+++ b/tests/src/Kernel/ConstraintTest.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Drupal\Tests\video_embed_field\Kernel;
+
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\simpletest\UserCreationTrait;
+use Drupal\video_embed_field\Plugin\Validation\Constraint\VideoEmbedConstraint;
+
+/**
+ * Test for the video embed constraint.
+ *
+ * @group video_embed_field
+ */
+class ConstraintTest extends KernelTestBase {
+
+  use UserCreationTrait;
+
+  /**
+   * A test user.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $user;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installEntitySchema('user');
+    $this->installSchema('system', ['sequences']);
+
+    $this->user = $this->createUser([]);
+  }
+
+  /**
+   * Test the video embed constraint.
+   */
+  public function testConstraint() {
+    $entity = EntityTest::create(['user_id' => $this->user->id()]);
+    $entity->{$this->fieldName}->value = 'invalid URL';
+    $violations = $entity->validate();
+
+    $this->assertCount(1, $violations);
+    $this->assertInstanceOf(VideoEmbedConstraint::class, $violations[0]->getConstraint());
+
+    $entity->{$this->fieldName}->value = 'https://youtube.com/watch?v=fdbFV_Wup-Ssw';
+    $violations = $entity->validate();
+    $this->assertCount(0, $violations);
+  }
+
+}