diff --git a/core/composer.json b/core/composer.json
index 5d248a188e..92f98c3842 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -35,7 +35,7 @@
         "twig/twig": "^1.38.2",
         "doctrine/common": "^2.5",
         "doctrine/annotations": "^1.2",
-        "guzzlehttp/guzzle": "^6.2.1",
+        "guzzlehttp/guzzle": "^6.3",
         "symfony-cmf/routing": "^1.4",
         "easyrdf/easyrdf": "^0.9",
         "zendframework/zend-feed": "^2.4",
@@ -46,7 +46,7 @@
         "zendframework/zend-diactoros": "^1.1",
         "composer/semver": "^1.0",
         "asm89/stack-cors": "^1.1",
-        "pear/archive_tar": "^1.4"
+        "pear/archive_tar": "^1.4.5"
     },
     "conflict": {
         "drush/drush": "<8.1.10"
diff --git a/core/drupalci.yml b/core/drupalci.yml
index 2085b9737b..b92a5e7948 100644
--- a/core/drupalci.yml
+++ b/core/drupalci.yml
@@ -14,6 +14,8 @@ build:
         # phpcs will use core's specified version of Coder.
         sniff-all-files: false
         halt-on-fail: false
+      container_command:
+        commands: "cd ${SOURCE_DIR} && rm -rf vendor/drupal/coder && composer update -n --prefer-lowest --no-progress"
     testing:
       # run_tests task is executed several times in order of performance speeds.
       # halt-on-fail can be set on the run_tests tasks in order to fail fast.
diff --git a/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php b/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
index f26d333cfc..df3e88c264 100644
--- a/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
+++ b/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
@@ -125,7 +125,10 @@ public static function getSkippedDeprecations() {
       'The Drupal\migrate\Plugin\migrate\process\Migration is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Instead, use Drupal\migrate\Plugin\migrate\process\MigrationLookup',
       'Passing in arguments the legacy way is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Provide the right parameter names in the method, similar to controllers. See https://www.drupal.org/node/2894819',
       'The "serializer.normalizer.file_entity.hal" normalizer service is deprecated: it is obsolete, it only remains available for backwards compatibility.',
+      // The following two deprecations are the same but different versions of
+      // Symfony have a slightly different wording. Need to skip both.
       'The Symfony\Component\ClassLoader\ApcClassLoader class is deprecated since Symfony 3.3 and will be removed in 4.0. Use `composer install --apcu-autoloader` instead.',
+      'The Symfony\Component\ClassLoader\ApcClassLoader class is deprecated since version 3.3 and will be removed in 4.0. Use `composer install --apcu-autoloader` instead.',
       // The following deprecation is not triggered by DrupalCI testing since it
       // is a Windows only deprecation. Remove when core no longer uses
       // WinCacheClassLoader in \Drupal\Core\DrupalKernel::initializeSettings().