diff --git a/dev/tests/integration/etc/install-config-mysql.php.dist b/dev/tests/integration/etc/install-config-mysql.php.dist
index 981d1bd073419ac3d82321d7abdd012441ffb77b..6fffcb22b50007191b510824bcf49c479dcae746 100644
--- a/dev/tests/integration/etc/install-config-mysql.php.dist
+++ b/dev/tests/integration/etc/install-config-mysql.php.dist
@@ -7,7 +7,7 @@
 return [
     'db-host' => 'localhost',
     'db-user' => 'root',
-    'db-password' => 'vagrant',
+    'db-password' => '123123q',
     'db-name' => 'magento_integration_tests',
     'db-prefix' => '',
     'backend-frontname' => 'backend',
diff --git a/lib/internal/Magento/Framework/App/ResourceConnection/Config.php b/lib/internal/Magento/Framework/App/ResourceConnection/Config.php
index da0b4d3b033e41e3e3fc694052482bdba935b766..79500c4b1073e57a9abfa91f74edac931c0a8eaa 100644
--- a/lib/internal/Magento/Framework/App/ResourceConnection/Config.php
+++ b/lib/internal/Magento/Framework/App/ResourceConnection/Config.php
@@ -21,6 +21,8 @@ class Config extends \Magento\Framework\Config\Data\Scoped implements ConfigInte
     protected $_connectionNames = [];
 
     /**
+     * Constructor
+     *
      * @param Config\Reader $reader
      * @param \Magento\Framework\Config\ScopeInterface $configScope
      * @param \Magento\Framework\Config\CacheInterface $cache
diff --git a/lib/internal/Magento/Framework/Config/Data.php b/lib/internal/Magento/Framework/Config/Data.php
index 57b6769d3e559629b99098a7eaa422bef6dc8323..1169abafccd8f2d868d2d56c821a67a761368f38 100644
--- a/lib/internal/Magento/Framework/Config/Data.php
+++ b/lib/internal/Magento/Framework/Config/Data.php
@@ -68,7 +68,7 @@ class Data implements \Magento\Framework\Config\DataInterface
     /**
      * @var SerializerInterface
      */
-    protected $serializer;
+    private $serializer;
 
     /**
      * Constructor
diff --git a/lib/internal/Magento/Framework/Config/Data/Scoped.php b/lib/internal/Magento/Framework/Config/Data/Scoped.php
index 02379834c5e78f57105391a323561a7255422d46..f9c151e867b89726ccea1f46ed269931efee51da 100644
--- a/lib/internal/Magento/Framework/Config/Data/Scoped.php
+++ b/lib/internal/Magento/Framework/Config/Data/Scoped.php
@@ -55,6 +55,11 @@ class Scoped extends \Magento\Framework\Config\Data
      */
     protected $_loadedScopes = [];
 
+    /**
+     * @var SerializerInterface
+     */
+    private $serializer;
+
     /**
      * Constructor
      *
diff --git a/lib/internal/Magento/Framework/Interception/PluginList/PluginList.php b/lib/internal/Magento/Framework/Interception/PluginList/PluginList.php
index dc3ddea2c6fa80696747dfbe83a653d5af77ab8f..eacd4e84932370bbea9d3be45420d562220d9980 100644
--- a/lib/internal/Magento/Framework/Interception/PluginList/PluginList.php
+++ b/lib/internal/Magento/Framework/Interception/PluginList/PluginList.php
@@ -82,6 +82,11 @@ class PluginList extends Scoped implements InterceptionPluginList
      */
     private $logger;
 
+    /**
+     * @var SerializerInterface
+     */
+    private $serializer;
+
     /**
      * Constructor
      *
@@ -111,8 +116,8 @@ class PluginList extends Scoped implements InterceptionPluginList
         $cacheId = 'plugins',
         SerializerInterface $serializer = null
     ) {
-        $serializer = $serializer ?: $objectManager->get(Serialize::class);
-        parent::__construct($reader, $configScope, $cache, $cacheId, $serializer);
+        $this->serializer = $serializer ?: $objectManager->get(Serialize::class);
+        parent::__construct($reader, $configScope, $cache, $cacheId, $this->serializer);
         $this->_omConfig = $omConfig;
         $this->_relations = $relations;
         $this->_definitions = $definitions;