diff --git a/core/composer.json b/core/composer.json
index 797a9f9e37..c4bb384b92 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -44,7 +44,7 @@
         "jcalderonzumba/gastonjs": "^1.0.2",
         "jcalderonzumba/mink-phantomjs-driver": "^0.3.1",
         "mikey179/vfsStream": "^1.2",
-        "phpunit/phpunit": "^4.8.35 || ^6.0",
+        "phpunit/phpunit": "^4.8.35 || ^6.1",
         "phpspec/prophecy": "^1.4",
         "symfony/css-selector": "~3.2.8",
         "symfony/phpunit-bridge": "^3.4.0@beta"
diff --git a/core/lib/Drupal/Core/Composer/Composer.php b/core/lib/Drupal/Core/Composer/Composer.php
index 9d3d386596..5f3a4a92ab 100644
--- a/core/lib/Drupal/Core/Composer/Composer.php
+++ b/core/lib/Drupal/Core/Composer/Composer.php
@@ -162,7 +162,7 @@ public static function upgradePHPUnit(Event $event) {
 
     // If the PHP version is 7.2 or above and PHPUnit is less than version 6
     // call the drupal-phpunit-upgrade script to upgrade PHPUnit.
-    if (version_compare(PHP_MAJOR_VERSION . '.' . PHP_MINOR_VERSION, '7.2') >= 0 && version_compare($phpunit_package->getVersion(), '6.0') < 0) {
+    if (version_compare(PHP_MAJOR_VERSION . '.' . PHP_MINOR_VERSION, '7.2') >= 0 && version_compare($phpunit_package->getVersion(), '6.1') < 0) {
       $event->getComposer()
         ->getEventDispatcher()
         ->dispatchScript('drupal-phpunit-upgrade');
diff --git a/core/phpunit.xml.dist b/core/phpunit.xml.dist
index ed3216d369..963d921a7e 100644
--- a/core/phpunit.xml.dist
+++ b/core/phpunit.xml.dist
@@ -8,8 +8,7 @@
 <phpunit bootstrap="tests/bootstrap.php" colors="true"
          beStrictAboutTestsThatDoNotTestAnything="true"
          beStrictAboutOutputDuringTests="true"
-         beStrictAboutChangesToGlobalState="true"
-         checkForUnintentionallyCoveredCode="false">
+         beStrictAboutChangesToGlobalState="true">
 <!-- TODO set printerClass="\Drupal\Tests\Listeners\HtmlOutputPrinter" once
  https://youtrack.jetbrains.com/issue/WI-24808 is resolved. Drupal provides a
  result printer that links to the html output results for functional tests.
diff --git a/core/tests/bootstrap.php b/core/tests/bootstrap.php
index 731110aba0..50fef61ee6 100644
--- a/core/tests/bootstrap.php
+++ b/core/tests/bootstrap.php
@@ -8,6 +8,7 @@
  */
 
 use Drupal\Component\Assertion\Handle;
+use PHPUnit\Runner\Version;
 
 /**
  * Finds all valid extension directories recursively within a given directory.
@@ -167,40 +168,18 @@ function drupal_phpunit_populate_class_loader() {
 // not turn runtime assertions on if they weren't on already.
 Handle::register();
 
-// @todo Decide if we need put in some code for WebTestBase too since there are
-//   tests using PHPUnit_Util_XML for example.
 // PHPUnit 4 to PHPUnit 6 bridge. Tests written for PHPUnit 4 need to work on
 // PHPUnit 6 with a minimum of fuss.
-if (!class_exists('\PHPUnit_Framework_AssertionFailedError') && class_exists('\PHPUnit\Framework\AssertionFailedError')) {
+if (class_exists('PHPUnit\Runner\Version') && version_compare(Version::id(), '6.1', '>=')) {
   class_alias('\PHPUnit\Framework\AssertionFailedError', '\PHPUnit_Framework_AssertionFailedError');
-}
-if (!class_exists('\PHPUnit_Framework_Error_Warning') && class_exists('\PHPUnit\Framework\Error\Warning')) {
-  class_alias('\PHPUnit\Framework\Error\Warning', '\PHPUnit_Framework_Error_Warning');
-}
-if (!class_exists('\PHPUnit_Framework_Error') && class_exists('\PHPUnit\Framework\Error\Error')) {
+  class_alias('\PHPUnit\Framework\Constraint\Count', '\PHPUnit_Framework_Constraint_Count');
   class_alias('\PHPUnit\Framework\Error\Error', '\PHPUnit_Framework_Error');
-}
-if (!class_exists('\PHPUnit_Framework_TestCase') && class_exists('\PHPUnit\Framework\TestCase')) {
+  class_alias('\PHPUnit\Framework\Error\Warning', '\PHPUnit_Framework_Error_Warning');
+  class_alias('\PHPUnit\Framework\ExpectationFailedException', '\PHPUnit_Framework_ExpectationFailedException');
+  class_alias('\PHPUnit\Framework\Exception', '\PHPUnit_Framework_Exception');
+  class_alias('\PHPUnit\Framework\MockObject\Matcher\InvokedRecorder', '\PHPUnit_Framework_MockObject_Matcher_InvokedRecorder');
+  class_alias('\PHPUnit\Framework\SkippedTestError', '\PHPUnit_Framework_SkippedTestError');
   class_alias('\PHPUnit\Framework\TestCase', '\PHPUnit_Framework_TestCase');
-}
-if (!class_exists('\PHPUnit_Util_Test') && class_exists('\PHPUnit\Util\Test')) {
   class_alias('\PHPUnit\Util\Test', '\PHPUnit_Util_Test');
-}
-if (!class_exists('\PHPUnit_Util_XML') && class_exists('\PHPUnit\Util\XML')) {
   class_alias('\PHPUnit\Util\XML', '\PHPUnit_Util_XML');
 }
-if (!class_exists('\PHPUnit_Framework_SkippedTestError') && class_exists('\PHPUnit\Framework\SkippedTestError')) {
-  class_alias('\PHPUnit\Framework\SkippedTestError', '\PHPUnit_Framework_SkippedTestError');
-}
-if (!class_exists('\PHPUnit_Framework_Exception') && class_exists('\PHPUnit\Framework\Exception')) {
-  class_alias('\PHPUnit\Framework\Exception', '\PHPUnit_Framework_Exception');
-}
-if (!class_exists('\PHPUnit_Framework_ExpectationFailedException') && class_exists('\PHPUnit\Framework\ExpectationFailedException')) {
-  class_alias('\PHPUnit\Framework\ExpectationFailedException', '\PHPUnit_Framework_ExpectationFailedException');
-}
-if (!class_exists('\PHPUnit_Framework_Constraint_Count') && class_exists('\PHPUnit\Framework\Constraint\Count')) {
-  class_alias('\PHPUnit\Framework\Constraint\Count', '\PHPUnit_Framework_Constraint_Count');
-}
-if (!class_exists('\PHPUnit_Framework_MockObject_Matcher_InvokedRecorder') && class_exists('\PHPUnit\Framework\MockObject\Matcher\InvokedRecorder')) {
-  class_alias('\PHPUnit\Framework\MockObject\Matcher\InvokedRecorder', '\PHPUnit_Framework_MockObject_Matcher_InvokedRecorder');
-}