diff --git a/composer.lock b/composer.lock
index 117ea487ae..3bee95a24c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "content-hash": "97de1708c79f6205a295cfc9808c0c72",
+    "content-hash": "c02bb0f9e23277fde0b2daef71888bb7",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -1682,6 +1682,68 @@
             "homepage": "https://symfony.com",
             "time": "2017-05-01T17:46:48+00:00"
         },
+        {
+            "name": "symfony/phpunit-bridge",
+            "version": "v3.4.0-BETA2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/phpunit-bridge.git",
+                "reference": "9128796e0cc46f17973e7e9345eb34696aafe00b"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/phpunit-bridge/zipball/9128796e0cc46f17973e7e9345eb34696aafe00b",
+                "reference": "9128796e0cc46f17973e7e9345eb34696aafe00b",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3"
+            },
+            "conflict": {
+                "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0"
+            },
+            "suggest": {
+                "ext-zip": "Zip support is required when using bin/simple-phpunit",
+                "symfony/debug": "For tracking deprecated interfaces usages at runtime with DebugClassLoader"
+            },
+            "bin": [
+                "bin/simple-phpunit"
+            ],
+            "type": "symfony-bridge",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.4-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ],
+                "psr-4": {
+                    "Symfony\\Bridge\\PhpUnit\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony PHPUnit Bridge",
+            "homepage": "https://symfony.com",
+            "time": "2017-10-28T16:49:05+00:00"
+        },
         {
             "name": "symfony/polyfill-iconv",
             "version": "v1.3.0",
@@ -2801,7 +2863,7 @@
             "version": "8.2.12",
             "source": {
                 "type": "git",
-                "url": "https://github.com/klausi/coder.git",
+                "url": "https://git.drupal.org/project/coder.git",
                 "reference": "984c54a7b1e8f27ff1c32348df69712afd86b17f"
             },
             "dist": {
@@ -4191,75 +4253,12 @@
             "description": "Symfony DomCrawler Component",
             "homepage": "https://symfony.com",
             "time": "2017-04-12T14:13:17+00:00"
-        },
-        {
-            "name": "symfony/phpunit-bridge",
-            "version": "dev-master",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/symfony/phpunit-bridge.git",
-                "reference": "923c15c5a7dacb7f4289da9efb8013a1a246c562"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/symfony/phpunit-bridge/zipball/923c15c5a7dacb7f4289da9efb8013a1a246c562",
-                "reference": "923c15c5a7dacb7f4289da9efb8013a1a246c562",
-                "shasum": ""
-            },
-            "require": {
-                "php": ">=5.3.3"
-            },
-            "conflict": {
-                "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0"
-            },
-            "suggest": {
-                "ext-zip": "Zip support is required when using bin/simple-phpunit",
-                "symfony/debug": "For tracking deprecated interfaces usages at runtime with DebugClassLoader"
-            },
-            "bin": [
-                "bin/simple-phpunit"
-            ],
-            "type": "symfony-bridge",
-            "extra": {
-                "branch-alias": {
-                    "dev-master": "4.0-dev"
-                }
-            },
-            "autoload": {
-                "files": [
-                    "bootstrap.php"
-                ],
-                "psr-4": {
-                    "Symfony\\Bridge\\PhpUnit\\": ""
-                },
-                "exclude-from-classmap": [
-                    "/Tests/"
-                ]
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Nicolas Grekas",
-                    "email": "p@tchwork.com"
-                },
-                {
-                    "name": "Symfony Community",
-                    "homepage": "https://symfony.com/contributors"
-                }
-            ],
-            "description": "Symfony PHPUnit Bridge",
-            "homepage": "https://symfony.com",
-            "time": "2017-10-25T09:57:11+00:00"
         }
     ],
     "aliases": [],
     "minimum-stability": "dev",
     "stability-flags": {
-        "behat/mink": 20,
-        "symfony/phpunit-bridge": 20
+        "behat/mink": 20
     },
     "prefer-stable": true,
     "prefer-lowest": false,
diff --git a/core/composer.json b/core/composer.json
index ebd629ccff..9ef6809ff7 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -47,7 +47,7 @@
         "phpunit/phpunit": ">=4.8.35 <5",
         "phpspec/prophecy": "^1.4",
         "symfony/css-selector": "~3.2.8",
-        "symfony/phpunit-bridge": "dev-master"
+        "symfony/phpunit-bridge": "^3.4.0-BETA2"
     },
     "replace": {
         "drupal/action": "self.version",
diff --git a/core/tests/bootstrap.php b/core/tests/bootstrap.php
index 5114890e33..f78b69ff04 100644
--- a/core/tests/bootstrap.php
+++ b/core/tests/bootstrap.php
@@ -8,7 +8,6 @@
  */
 
 use Drupal\Component\Assertion\Handle;
-use Symfony\Bridge\PhpUnit\DeprecationErrorHandler;
 
 /**
  * Finds all valid extension directories recursively within a given directory.
@@ -167,11 +166,3 @@ function drupal_phpunit_populate_class_loader() {
 // make PHP 5 and 7 handle assertion failures the same way, but this call does
 // not turn runtime assertions on if they weren't on already.
 Handle::register();
-
-// Enable the collection of deprecation notices in isolated PHPUnit tests.
-// We need to add this here because the assumptions made in
-// vendor/symfony/phpunit-bridge/bootstrap.php are not true for Drupal. We set
-// PHPUNIT_COMPOSER_INSTALL during isolated test runs.
-if ($file = getenv('SYMFONY_DEPRECATIONS_SERIALIZE')) {
-  DeprecationErrorHandler::collectDeprecations($file);
-}