diff --git a/core/modules/rest/src/Plugin/rest/resource/EntityResource.php b/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
index 0b2c89a..dfb0272 100644
--- a/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
+++ b/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
@@ -10,9 +10,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityStorageException;
 use Drupal\rest\Plugin\ResourceBase;
-use Drupal\rest\ResourceAccessTrait;
 use Drupal\rest\ResourceResponse;
-use Drupal\rest\ResourceValidationTrait;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\rest\ModifiedResourceResponse;
@@ -38,8 +36,8 @@
  */
 class EntityResource extends ResourceBase implements DependentPluginInterface {
 
-  use ResourceValidationTrait;
-  use ResourceAccessTrait;
+  use EntityResourceValidationTrait;
+  use EntityResourceAccessTrait;
 
   /**
    * The entity type targeted by this resource.
diff --git a/core/modules/rest/src/ResourceAccessTrait.php b/core/modules/rest/src/Plugin/rest/resource/EntityResourceAccessTrait.php
similarity index 92%
rename from core/modules/rest/src/ResourceAccessTrait.php
rename to core/modules/rest/src/Plugin/rest/resource/EntityResourceAccessTrait.php
index c7943fa..3851221 100644
--- a/core/modules/rest/src/ResourceAccessTrait.php
+++ b/core/modules/rest/src/Plugin/rest/resource/EntityResourceAccessTrait.php
@@ -1,11 +1,11 @@
 <?php
 
-namespace Drupal\rest;
+namespace Drupal\rest\Plugin\rest\resource;
 
 use Drupal\Core\Entity\EntityInterface;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 
-trait ResourceAccessTrait {
+trait EntityResourceAccessTrait {
 
   /**
    * Performs edit access checks for fields.
diff --git a/core/modules/rest/src/ResourceValidationTrait.php b/core/modules/rest/src/Plugin/rest/resource/EntityResourceValidationTrait.php
similarity index 93%
rename from core/modules/rest/src/ResourceValidationTrait.php
rename to core/modules/rest/src/Plugin/rest/resource/EntityResourceValidationTrait.php
index 3502f45..323cb7d 100644
--- a/core/modules/rest/src/ResourceValidationTrait.php
+++ b/core/modules/rest/src/Plugin/rest/resource/EntityResourceValidationTrait.php
@@ -1,12 +1,12 @@
 <?php
 
-namespace Drupal\rest;
+namespace Drupal\rest\Plugin\rest\resource;
 
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Symfony\Component\HttpKernel\Exception\UnprocessableEntityHttpException;
 
-trait ResourceValidationTrait {
+trait EntityResourceValidationTrait {
 
   /**
    * Verifies that the whole entity does not violate any validation constraints.
diff --git a/core/modules/rest/tests/src/Unit/ResourceValidationTraitTest.php b/core/modules/rest/tests/src/Unit/EntityResourceValidationTraitTest.php
similarity index 84%
rename from core/modules/rest/tests/src/Unit/ResourceValidationTraitTest.php
rename to core/modules/rest/tests/src/Unit/EntityResourceValidationTraitTest.php
index 51cf5c0..20a6175 100644
--- a/core/modules/rest/tests/src/Unit/ResourceValidationTraitTest.php
+++ b/core/modules/rest/tests/src/Unit/EntityResourceValidationTraitTest.php
@@ -11,15 +11,15 @@
 
 /**
  * @group rest
- * @coversDefaultClass \Drupal\rest\ResourceValidationTrait
+ * @coversDefaultClass \Drupal\rest\Plugin\rest\resource\EntityResourceValidationTrait
  */
-class ResourceValidationTraitTest extends UnitTestCase {
+class EntityResourceValidationTraitTest extends UnitTestCase {
 
   /**
    * @covers ::validate
    */
   public function testValidate() {
-    $trait = $this->getMockForTrait('Drupal\rest\ResourceValidationTrait');
+    $trait = $this->getMockForTrait('Drupal\rest\Plugin\rest\resource\EntityResourceValidationTrait');
 
     $method = new \ReflectionMethod($trait, 'validate');
     $method->setAccessible(TRUE);
@@ -60,7 +60,7 @@ public function testFailedValidate() {
 
     $entity->validate()->willReturn($violations);
 
-    $trait = $this->getMockForTrait('Drupal\rest\ResourceValidationTrait');
+    $trait = $this->getMockForTrait('Drupal\rest\Plugin\rest\resource\EntityResourceValidationTrait');
 
     $method = new \ReflectionMethod($trait, 'validate');
     $method->setAccessible(TRUE);
diff --git a/core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php b/core/modules/user/src/Plugin/rest/resource/UserRegistrationResource.php
similarity index 96%
rename from core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php
rename to core/modules/user/src/Plugin/rest/resource/UserRegistrationResource.php
index 362003a..6a243c3 100644
--- a/core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php
+++ b/core/modules/user/src/Plugin/rest/resource/UserRegistrationResource.php
@@ -1,19 +1,18 @@
 <?php
 
-namespace Drupal\rest\Plugin\rest\resource;
+namespace Drupal\user\Plugin\rest\resource;
 
 use Drupal\Core\Config\ImmutableConfig;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\rest\ModifiedResourceResponse;
-use Drupal\rest\ResourceAccessTrait;
+use Drupal\rest\Plugin\ResourceBase;
+use Drupal\rest\Plugin\rest\resource\EntityResourceAccessTrait;
+use Drupal\rest\Plugin\rest\resource\EntityResourceValidationTrait;
 use Drupal\user\UserInterface;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
-use Drupal\rest\Plugin\ResourceBase;
-use \Drupal\rest\ResourceValidationTrait;
-use Symfony\Component\HttpKernel\Exception\HttpException;
 use Symfony\Component\HttpKernel\Exception\UnprocessableEntityHttpException;
 
 /**
@@ -30,8 +29,8 @@
  */
 class UserRegistrationResource extends ResourceBase {
 
-  use ResourceValidationTrait;
-  use ResourceAccessTrait;
+  use EntityResourceValidationTrait;
+  use EntityResourceAccessTrait;
 
   /**
    * User settings config instance.
diff --git a/core/modules/rest/src/Tests/RegisterUserTest.php b/core/modules/user/src/Tests/RestRegisterUserTest.php
similarity index 97%
rename from core/modules/rest/src/Tests/RegisterUserTest.php
rename to core/modules/user/src/Tests/RestRegisterUserTest.php
index 2b14a6b..d8420ca 100644
--- a/core/modules/rest/src/Tests/RegisterUserTest.php
+++ b/core/modules/user/src/Tests/RestRegisterUserTest.php
@@ -1,16 +1,17 @@
 <?php
 
-namespace Drupal\rest\Tests;
+namespace Drupal\user\Tests;
 
+use Drupal\rest\Tests\RESTTestBase;
 use Drupal\user\Entity\Role;
 use Drupal\user\RoleInterface;
 
 /**
- * Tests user registration.
+ * Tests user registration via REST resource.
  *
- * @group rest
+ * @group user
  */
-class RegisterUserTest extends RESTTestBase {
+class RestRegisterUserTest extends RESTTestBase {
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Unit/UserRegistrationResourceTest.php b/core/modules/user/tests/src/Unit/UserRegistrationResourceTest.php
similarity index 94%
rename from core/modules/rest/tests/src/Unit/UserRegistrationResourceTest.php
rename to core/modules/user/tests/src/Unit/UserRegistrationResourceTest.php
index db22768..142685c 100644
--- a/core/modules/rest/tests/src/Unit/UserRegistrationResourceTest.php
+++ b/core/modules/user/tests/src/Unit/UserRegistrationResourceTest.php
@@ -1,12 +1,12 @@
 <?php
 
-namespace Drupal\Tests\rest\Unit;
+namespace Drupal\Tests\user\Unit;
 
 use Drupal\Core\Config\ImmutableConfig;
 use Drupal\Core\Session\AccountInterface;
-use Drupal\rest\Plugin\rest\resource\UserRegistrationResource;
 use Drupal\Tests\UnitTestCase;
 use Drupal\user\Entity\User;
+use Drupal\user\Plugin\rest\resource\UserRegistrationResource;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
@@ -36,8 +36,8 @@
 /**
  * Tests User Registration REST resource.
  *
- * @coversDefaultClass \Drupal\Tests\rest\Unit\UserRegistrationResourceTest
- * @group rest
+ * @coversDefaultClass \Drupal\user\Plugin\rest\resource\UserRegistrationResource
+ * @group user
  */
 class UserRegistrationResourceTest extends UnitTestCase {
 
@@ -46,7 +46,7 @@ class UserRegistrationResourceTest extends UnitTestCase {
   /**
    * Class to be tested.
    *
-   * @var \Drupal\rest\Plugin\rest\resource\UserRegistrationResource
+   * @var \Drupal\user\Plugin\rest\resource\UserRegistrationResource
    */
   protected $testClass;