diff --git a/core/includes/common.inc b/core/includes/common.inc
index 2def62d..851f3fb 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1,7 +1,7 @@
 <?php
 
 use Drupal\Component\Utility\Crypt;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\Number;
 use Drupal\Component\Utility\Settings;
 use Drupal\Component\Utility\SortArray;
@@ -2988,7 +2988,7 @@ function drupal_clear_js_cache() {
  * @ingroup php_wrappers
  *
  * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
- *   Use \Drupal\Component\Utility\Json::encode().
+ *   Use \Drupal\Core\Serialization\Json::encode().
  */
 function drupal_json_encode($var) {
   return Json::encode($var);
@@ -3002,7 +3002,7 @@ function drupal_json_encode($var) {
  * @ingroup php_wrappers
  *
  * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
- *   Use \Drupal\Component\Utility\Json::decode().
+ *   Use \Drupal\Core\Serialization\Json::decode().
  */
 function drupal_json_decode($var) {
   return Json::decode($var);
diff --git a/core/lib/Drupal/Core/Asset/JsCollectionRenderer.php b/core/lib/Drupal/Core/Asset/JsCollectionRenderer.php
index cdaf1d8..a3b3a42 100644
--- a/core/lib/Drupal/Core/Asset/JsCollectionRenderer.php
+++ b/core/lib/Drupal/Core/Asset/JsCollectionRenderer.php
@@ -7,7 +7,7 @@
 namespace Drupal\Core\Asset;
 
 use Drupal\Core\KeyValueStore\StateInterface;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 
 /**
  * Renders JavaScript assets.
diff --git a/core/lib/Drupal/Component/Utility/Json.php b/core/lib/Drupal/Core/Serialization/Json.php
similarity index 92%
rename from core/lib/Drupal/Component/Utility/Json.php
rename to core/lib/Drupal/Core/Serialization/Json.php
index 88e55ae..20427b4 100644
--- a/core/lib/Drupal/Component/Utility/Json.php
+++ b/core/lib/Drupal/Core/Serialization/Json.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\Component\Utility\Json.
+ * Contains \Drupal\Core\Serialization\Json.
  */
 
-namespace Drupal\Component\Utility;
+namespace Drupal\Core\Serialization;
 
 /**
  * Provides helpers for dealing with json.
diff --git a/core/lib/Drupal/Core/Utility/LinkGenerator.php b/core/lib/Drupal/Core/Utility/LinkGenerator.php
index 1ebc5bf..70c2bed 100644
--- a/core/lib/Drupal/Core/Utility/LinkGenerator.php
+++ b/core/lib/Drupal/Core/Utility/LinkGenerator.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Utility;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Path\AliasManagerInterface;
diff --git a/core/modules/block/lib/Drupal/block/BlockListBuilder.php b/core/modules/block/lib/Drupal/block/BlockListBuilder.php
index 31b3286..00b2780 100644
--- a/core/modules/block/lib/Drupal/block/BlockListBuilder.php
+++ b/core/modules/block/lib/Drupal/block/BlockListBuilder.php
@@ -8,7 +8,7 @@
 namespace Drupal\block;
 
 use Drupal\Component\Plugin\PluginManagerInterface;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
diff --git a/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php b/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php
index ab13127..973bd75 100644
--- a/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\block\Tests\Views;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\String;
 use Drupal\views\Views;
 use Drupal\views\Tests\ViewTestBase;
diff --git a/core/modules/comment/lib/Drupal/comment/Tests/CommentNewIndicatorTest.php b/core/modules/comment/lib/Drupal/comment/Tests/CommentNewIndicatorTest.php
index 2a3a957..60d093b 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/CommentNewIndicatorTest.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentNewIndicatorTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\comment\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Language\Language;
 use Drupal\comment\CommentInterface;
 
diff --git a/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php b/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
index 405aaf5..e5f7c8e 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\config_translation\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Config\FileStorage;
 use Drupal\Core\Language\Language;
diff --git a/core/modules/content_translation/lib/Drupal/content_translation/Tests/ContentTranslationContextualLinksTest.php b/core/modules/content_translation/lib/Drupal/content_translation/Tests/ContentTranslationContextualLinksTest.php
index 4b71a16..c25d480 100644
--- a/core/modules/content_translation/lib/Drupal/content_translation/Tests/ContentTranslationContextualLinksTest.php
+++ b/core/modules/content_translation/lib/Drupal/content_translation/Tests/ContentTranslationContextualLinksTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\content_translation\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\node\Entity\NodeType;
 use Drupal\simpletest\WebTestBase;
 
diff --git a/core/modules/contextual/contextual.module b/core/modules/contextual/contextual.module
index 30017b0..d49045a 100644
--- a/core/modules/contextual/contextual.module
+++ b/core/modules/contextual/contextual.module
@@ -5,7 +5,7 @@
  * Adds contextual links to perform actions related to elements on a page.
  */
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Core\Template\Attribute;
 
diff --git a/core/modules/contextual/lib/Drupal/contextual/Plugin/views/field/ContextualLinks.php b/core/modules/contextual/lib/Drupal/contextual/Plugin/views/field/ContextualLinks.php
index 2f6004a..fd41e5d 100644
--- a/core/modules/contextual/lib/Drupal/contextual/Plugin/views/field/ContextualLinks.php
+++ b/core/modules/contextual/lib/Drupal/contextual/Plugin/views/field/ContextualLinks.php
@@ -9,7 +9,7 @@
 
 use Drupal\views\Plugin\views\field\FieldPluginBase;
 use Drupal\views\ResultRow;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 
 /**
  * Provides a handler that adds contextual links.
diff --git a/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php b/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php
index 4e1e6d0..9ea933c 100644
--- a/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php
+++ b/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\contextual\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 use Drupal\Core\Template\Attribute;
 
diff --git a/core/modules/edit/lib/Drupal/edit/Tests/EditAutocompleteTermTest.php b/core/modules/edit/lib/Drupal/edit/Tests/EditAutocompleteTermTest.php
index 803b0e3..0532bb5 100644
--- a/core/modules/edit/lib/Drupal/edit/Tests/EditAutocompleteTermTest.php
+++ b/core/modules/edit/lib/Drupal/edit/Tests/EditAutocompleteTermTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\edit\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Language\Language;
 use Drupal\simpletest\WebTestBase;
diff --git a/core/modules/edit/lib/Drupal/edit/Tests/EditLoadingTest.php b/core/modules/edit/lib/Drupal/edit/Tests/EditLoadingTest.php
index 6ee7cee..7a99be7 100644
--- a/core/modules/edit/lib/Drupal/edit/Tests/EditLoadingTest.php
+++ b/core/modules/edit/lib/Drupal/edit/Tests/EditLoadingTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\edit\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 use Drupal\edit\Ajax\MetadataCommand;
 use Drupal\Core\Ajax\AppendCommand;
diff --git a/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationLoadingTest.php b/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationLoadingTest.php
index a66a461..a6f4ac1 100644
--- a/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationLoadingTest.php
+++ b/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationLoadingTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\editor\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationTest.php b/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationTest.php
index b0075d2..dfff415 100644
--- a/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationTest.php
+++ b/core/modules/editor/lib/Drupal/editor/Tests/EditIntegrationTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\editor\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Language\Language;
 use Drupal\edit\EditorSelector;
 use Drupal\edit\MetadataGenerator;
diff --git a/core/modules/editor/lib/Drupal/editor/Tests/EditorSecurityTest.php b/core/modules/editor/lib/Drupal/editor/Tests/EditorSecurityTest.php
index 39670cc..e787d2f 100644
--- a/core/modules/editor/lib/Drupal/editor/Tests/EditorSecurityTest.php
+++ b/core/modules/editor/lib/Drupal/editor/Tests/EditorSecurityTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\editor\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 use Drupal\Component\Utility\String;
 
diff --git a/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceAutocompleteTest.php b/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceAutocompleteTest.php
index 7c7ba59..c9a1ed6 100644
--- a/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceAutocompleteTest.php
+++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceAutocompleteTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\entity_reference\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\String;
 use Drupal\Component\Utility\Tags;
 use Drupal\entity_reference\EntityReferenceController;
diff --git a/core/modules/history/lib/Drupal/history/Tests/HistoryTest.php b/core/modules/history/lib/Drupal/history/Tests/HistoryTest.php
index 88d3866..1506583 100644
--- a/core/modules/history/lib/Drupal/history/Tests/HistoryTest.php
+++ b/core/modules/history/lib/Drupal/history/Tests/HistoryTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\history\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index 68a4d1d..7519f60 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -10,7 +10,7 @@
  * object files are supported.
  */
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Language\Language;
 use Drupal\Component\Utility\Crypt;
diff --git a/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php b/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php
index f6461c9..658fcec 100644
--- a/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php
+++ b/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\menu\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 
 /**
  * Defines a test class for testing menu and menu link functionality.
diff --git a/core/modules/node/lib/Drupal/node/Tests/Views/NodeContextualLinksTest.php b/core/modules/node/lib/Drupal/node/Tests/Views/NodeContextualLinksTest.php
index ff390e6..965d56f 100644
--- a/core/modules/node/lib/Drupal/node/Tests/Views/NodeContextualLinksTest.php
+++ b/core/modules/node/lib/Drupal/node/Tests/Views/NodeContextualLinksTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\node\Tests\Views;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
diff --git a/core/modules/rest/lib/Drupal/rest/Tests/CreateTest.php b/core/modules/rest/lib/Drupal/rest/Tests/CreateTest.php
index e33aebc..0d8d9b4 100644
--- a/core/modules/rest/lib/Drupal/rest/Tests/CreateTest.php
+++ b/core/modules/rest/lib/Drupal/rest/Tests/CreateTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\rest\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 
 /**
  * Tests resource creation on user, node and test entities.
diff --git a/core/modules/rest/lib/Drupal/rest/Tests/DBLogTest.php b/core/modules/rest/lib/Drupal/rest/Tests/DBLogTest.php
index 53e5ed7..83f24b6 100644
--- a/core/modules/rest/lib/Drupal/rest/Tests/DBLogTest.php
+++ b/core/modules/rest/lib/Drupal/rest/Tests/DBLogTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\rest\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\rest\Tests\RESTTestBase;
 
 /**
diff --git a/core/modules/rest/lib/Drupal/rest/Tests/ReadTest.php b/core/modules/rest/lib/Drupal/rest/Tests/ReadTest.php
index 44c5e15..c7cf4a7 100644
--- a/core/modules/rest/lib/Drupal/rest/Tests/ReadTest.php
+++ b/core/modules/rest/lib/Drupal/rest/Tests/ReadTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\rest\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Language\Language;
 use Drupal\rest\Tests\RESTTestBase;
 
diff --git a/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php b/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php
index adff21d..9a60acc 100644
--- a/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php
+++ b/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\rest\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\rest\Tests\RESTTestBase;
 
 /**
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 8efa40a..011a6b2 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -8,7 +8,7 @@
 namespace Drupal\simpletest;
 
 use Drupal\Component\Utility\Crypt;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Component\Utility\String;
 use Drupal\Core\DrupalKernel;
diff --git a/core/modules/system/lib/Drupal/system/Controller/SystemController.php b/core/modules/system/lib/Drupal/system/Controller/SystemController.php
index 361f716..30770df 100644
--- a/core/modules/system/lib/Drupal/system/Controller/SystemController.php
+++ b/core/modules/system/lib/Drupal/system/Controller/SystemController.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Controller;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Entity\Query\QueryFactory;
 use Drupal\Core\Extension\ThemeHandlerInterface;
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/JavaScriptTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/JavaScriptTest.php
index 0881810..5d8ba2b 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/JavaScriptTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/JavaScriptTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\Common;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\DrupalUnitTestBase;
 use Drupal\Component\Utility\Crypt;
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
index b0616d5..613b354 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
@@ -8,7 +8,7 @@
 namespace Drupal\system\Tests\Common;
 
 use Drupal\Component\Utility\Html;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\DrupalUnitTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/EmailTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/EmailTest.php
index dd80f29..cfb7036 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/EmailTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/EmailTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\Form;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php
index e2ef22c..8e389a2 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\Form;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\String;
 use Drupal\simpletest\WebTestBase;
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/LanguageSelectElementTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/LanguageSelectElementTest.php
index 0acd6b2..92c3258 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/LanguageSelectElementTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/LanguageSelectElementTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\Form;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 use Drupal\Core\Language\Language;
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/StateValuesCleanTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/StateValuesCleanTest.php
index e6f844f..5cd6546 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/StateValuesCleanTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/StateValuesCleanTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\Form;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/UrlTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/UrlTest.php
index a068adc..74a2cd4 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/UrlTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/UrlTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\Form;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/system/tests/Drupal/system/Tests/Controller/SystemControllerTest.php b/core/modules/system/tests/Drupal/system/Tests/Controller/SystemControllerTest.php
index fb5dc88..a4ffe61 100644
--- a/core/modules/system/tests/Drupal/system/Tests/Controller/SystemControllerTest.php
+++ b/core/modules/system/tests/Drupal/system/Tests/Controller/SystemControllerTest.php
@@ -8,7 +8,7 @@
 namespace Drupal\system\Tests\Controller;
 
 use Symfony\Component\HttpFoundation\Request;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Template\Attribute;
 use Drupal\system\Controller\SystemController;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/system/tests/modules/form_test/form_test.module b/core/modules/system/tests/modules/form_test/form_test.module
index de5c2f0..dc65d0d 100644
--- a/core/modules/system/tests/modules/form_test/form_test.module
+++ b/core/modules/system/tests/modules/form_test/form_test.module
@@ -5,7 +5,7 @@
  * Helper module for the form API tests.
  */
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Database\Database;
 use Drupal\Core\Language\Language;
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/TermTest.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/TermTest.php
index 23c0781..c48e1ca 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/TermTest.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/TermTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\taxonomy\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\Tags;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Component\Utility\String;
diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewAjaxTest.php b/core/modules/views/lib/Drupal/views/Tests/ViewAjaxTest.php
index d8728d1..af2307f 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewAjaxTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewAjaxTest.php
@@ -6,7 +6,7 @@
  */
 
 namespace Drupal\views\Tests;
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 
 /**
  * Tests the ajax view functionality.
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/Tests/DisplayTest.php b/core/modules/views_ui/lib/Drupal/views_ui/Tests/DisplayTest.php
index b3edc9a..b3d4d7f 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/Tests/DisplayTest.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/Tests/DisplayTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\views_ui\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Component\Utility\String;
 
 use Drupal\views\Views;
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/Tests/PreviewTest.php b/core/modules/views_ui/lib/Drupal/views_ui/Tests/PreviewTest.php
index d8b6a65..a1e92da 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/Tests/PreviewTest.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/Tests/PreviewTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\views_ui\Tests;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 
 /**
  * Tests the preview form in the UI.
diff --git a/core/tests/Drupal/Tests/Component/Utility/JsonTest.php b/core/tests/Drupal/Tests/Core/Serialization/JsonTest.php
similarity index 95%
rename from core/tests/Drupal/Tests/Component/Utility/JsonTest.php
rename to core/tests/Drupal/Tests/Core/Serialization/JsonTest.php
index c1a8343..dcc8951 100644
--- a/core/tests/Drupal/Tests/Component/Utility/JsonTest.php
+++ b/core/tests/Drupal/Tests/Core/Serialization/JsonTest.php
@@ -2,18 +2,18 @@
 
 /**
  * @file
- * Contains \Drupal\Tests\Component\Utility\JsonTest.
+ * Contains \Drupal\Tests\Core\Serialization\JsonTest.
  */
 
-namespace Drupal\Tests\Component\Utility;
+namespace Drupal\Tests\Core\Serialization;
 
-use Drupal\Component\Utility\Json;
+use Drupal\Core\Serialization\Json;
 use Drupal\Tests\UnitTestCase;
 
 /**
  * Tests the Json::encode() and Json::decode() functions.
  *
- * @see \Drupal\Component\Utility\Json
+ * @see \Drupal\Core\Serialization\Json
  */
 class JsonTest extends UnitTestCase {