diff --git a/composer.lock b/composer.lock
index 4554394d98..b2bbd57208 100644
--- a/composer.lock
+++ b/composer.lock
@@ -904,7 +904,7 @@
             "dist": {
                 "type": "path",
                 "url": "core",
-                "reference": "7aab842900eb46fc64009abe2819bc83529f3e58"
+                "reference": "66ebbd7f96eecc116bb75837a1ee47352d663c48"
             },
             "require": {
                 "asm89/stack-cors": "^1.1",
@@ -932,6 +932,7 @@
                 "php": ">=7.0.8",
                 "stack/builder": "^1.0",
                 "symfony-cmf/routing": "^1.4|^2.1",
+                "symfony/class-loader": "~3.4.0",
                 "symfony/console": "^4.4",
                 "symfony/dependency-injection": "^4.4",
                 "symfony/event-dispatcher": "^4.4",
@@ -2042,6 +2043,62 @@
             ],
             "time": "2018-06-14T06:42:21+00:00"
         },
+        {
+            "name": "symfony/class-loader",
+            "version": "v3.4.32",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/class-loader.git",
+                "reference": "e212b06996819a2bce026a63da03b7182d05a690"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/class-loader/zipball/e212b06996819a2bce026a63da03b7182d05a690",
+                "reference": "e212b06996819a2bce026a63da03b7182d05a690",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^5.5.9|>=7.0.8"
+            },
+            "require-dev": {
+                "symfony/finder": "~2.8|~3.0|~4.0",
+                "symfony/polyfill-apcu": "~1.1"
+            },
+            "suggest": {
+                "symfony/polyfill-apcu": "For using ApcClassLoader on HHVM"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.4-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\ClassLoader\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony ClassLoader Component",
+            "homepage": "https://symfony.com",
+            "time": "2019-08-20T13:31:17+00:00"
+        },
         {
             "name": "symfony/console",
             "version": "4.4.x-dev",
diff --git a/core/composer.json b/core/composer.json
index 2938bef2e3..bcc002b502 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -18,6 +18,7 @@
         "ext-tokenizer": "*",
         "ext-xml": "*",
         "php": ">=7.0.8",
+        "symfony/class-loader": "~3.4.0",
         "symfony/console": "^4.4",
         "symfony/dependency-injection": "^4.4",
         "symfony/event-dispatcher": "^4.4",