diff --git a/lib/internal/Magento/Framework/App/Test/Unit/ResourceConnection/ConfigTest.php b/lib/internal/Magento/Framework/App/Test/Unit/ResourceConnection/ConfigTest.php
index 62938aceae2cc7f54019a3df538626bb8303e92b..63823943537492dc6a9d55054c9aa0597136b4f8 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/ResourceConnection/ConfigTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/ResourceConnection/ConfigTest.php
@@ -27,6 +27,11 @@ class ConfigTest extends \PHPUnit_Framework_TestCase
      */
     private $readerMock;
 
+    /**
+     * @var \Magento\Framework\Serialize\SerializerInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $serializerMock;
+
     /**
      * @var array
      */
@@ -39,7 +44,6 @@ class ConfigTest extends \PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
         $this->scopeMock = $this->getMock(\Magento\Framework\Config\ScopeInterface::class);
         $this->cacheMock = $this->getMock(\Magento\Framework\Config\CacheInterface::class);
 
@@ -50,7 +54,7 @@ class ConfigTest extends \PHPUnit_Framework_TestCase
             '',
             false
         );
-        $serializerMock = $this->getMock(\Magento\Framework\Serialize\SerializerInterface::class);
+        $this->serializerMock = $this->getMock(\Magento\Framework\Serialize\SerializerInterface::class);
 
         $this->resourcesConfig = [
             'mainResourceName' => ['name' => 'mainResourceName', 'extends' => 'anotherResourceName'],
@@ -64,12 +68,12 @@ class ConfigTest extends \PHPUnit_Framework_TestCase
             'validResource' => ['connection' => 'validConnectionName'],
         ];
 
-        $jsonString = json_encode($this->resourcesConfig);
+        $serializedData = 'serialized data';
         $this->cacheMock->expects($this->any())
             ->method('load')
-            ->willReturn($jsonString);
-        $serializerMock->method('unserialize')
-            ->with($jsonString)
+            ->willReturn($serializedData);
+        $this->serializerMock->method('unserialize')
+            ->with($serializedData)
             ->willReturn($this->resourcesConfig);
 
         /**
@@ -86,15 +90,15 @@ class ConfigTest extends \PHPUnit_Framework_TestCase
             $this->scopeMock,
             $this->cacheMock,
             $deploymentConfigMock,
-            'cacheId'
+            'cacheId',
+            $this->serializerMock
         );
-        $objectManager->setBackwardCompatibleProperty($this->config, 'serializer', $serializerMock);
     }
 
     /**
-     * @dataProvider getConnectionNameDataProvider
      * @param string $resourceName
      * @param string $connectionName
+     * @dataProvider getConnectionNameDataProvider
      */
     public function testGetConnectionName($resourceName, $connectionName)
     {
@@ -117,7 +121,8 @@ class ConfigTest extends \PHPUnit_Framework_TestCase
             $this->scopeMock,
             $this->cacheMock,
             $deploymentConfigMock,
-            'cacheId'
+            'cacheId',
+            $this->serializerMock
         );
     }
 
diff --git a/lib/internal/Magento/Framework/Config/Data/Scoped.php b/lib/internal/Magento/Framework/Config/Data/Scoped.php
index 644c2649e4982ecf4b71d624191998942018bc9d..5e7bd441bbb296ac99d48c691995c8c9b5f4d376 100644
--- a/lib/internal/Magento/Framework/Config/Data/Scoped.php
+++ b/lib/internal/Magento/Framework/Config/Data/Scoped.php
@@ -104,12 +104,12 @@ class Scoped extends \Magento\Framework\Config\Data
                 if (false == isset($this->_loadedScopes[$scopeCode])) {
                     if ($scopeCode !== 'primary' && ($data = $this->_cache->load($scopeCode . '::' . $this->_cacheId))
                     ) {
-                        $data = $this->getSerializer()->unserialize($data);
+                        $data = $this->serializer->unserialize($data);
                     } else {
                         $data = $this->_reader->read($scopeCode);
                         if ($scopeCode !== 'primary') {
                             $this->_cache->save(
-                                $this->getSerializer()->serialize($data),
+                                $this->serializer->serialize($data),
                                 $scopeCode . '::' . $this->_cacheId
                             );
                         }