diff --git a/core/lib/Drupal/Core/Composer/Composer.php b/core/lib/Drupal/Core/Composer/Composer.php
index 3e2dc6f83b..8f030865e5 100644
--- a/core/lib/Drupal/Core/Composer/Composer.php
+++ b/core/lib/Drupal/Core/Composer/Composer.php
@@ -332,7 +332,7 @@ public static function upgradePHPUnit(Event $event) {
    *   TRUE if the PHPUnit needs to be upgraded, FALSE if not.
    */
   public static function upgradePHPUnitCheck($phpunit_version) {
-    return !(version_compare(PHP_MAJOR_VERSION . '.' . PHP_MINOR_VERSION, '8.1') >= 0 && version_compare($phpunit_version, '10.0') < 0);
+    return !(version_compare(PHP_MAJOR_VERSION . '.' . PHP_MINOR_VERSION, '8.1') >= 0 && version_compare($phpunit_version, '10') < 0);
   }
 
 }
diff --git a/core/phpunit.xml.dist b/core/phpunit.xml.dist
index 0425d8e51f..7ba22e820e 100644
--- a/core/phpunit.xml.dist
+++ b/core/phpunit.xml.dist
@@ -6,14 +6,15 @@
  or your current system user. See core/tests/README.md and
  https://www.drupal.org/node/2116263 for details.
 -->
-<phpunit bootstrap="tests/bootstrap.php" colors="true"
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         bootstrap="tests/bootstrap.php" colors="true"
          beStrictAboutTestsThatDoNotTestAnything="true"
          beStrictAboutOutputDuringTests="true"
          beStrictAboutChangesToGlobalState="true"
          failOnWarning="true"
          cacheResult="false"
          cacheDirectory=".phpunit.cache"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.0/phpunit.xsd">
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.0/phpunit.xsd">
   <php>
     <!-- Set error reporting to E_ALL. -->
     <ini name="error_reporting" value="32767"/>
diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index 9fe4bff2f7..7b82f5c0a4 100755
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -149,10 +149,10 @@
 }
 
 simpletest_script_print("PHP version: " . phpversion() . " - PHPUnit version: " . Version::id() . "\n", SIMPLETEST_SCRIPT_COLOR_PASS);
-//if (!Composer::upgradePHPUnitCheck(Version::id())) {
-//  simpletest_script_print_error("PHPUnit testing framework version 10 or greater is required when running on PHP 8.1 or greater. Run the command 'composer run-script drupal-phpunit-upgrade' in order to fix this.");
-//  exit(SIMPLETEST_SCRIPT_EXIT_FAILURE);
-//}
+if (!Composer::upgradePHPUnitCheck(Version::id())) {
+  simpletest_script_print_error("PHPUnit testing framework version 10 or greater is required when running on PHP 8.1 or greater. Run the command 'composer run-script drupal-phpunit-upgrade' in order to fix this.");
+  exit(SIMPLETEST_SCRIPT_EXIT_FAILURE);
+}
 
 $test_list = simpletest_script_get_test_list();
 
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/WebDriverTestBase.php b/core/tests/Drupal/FunctionalJavascriptTests/WebDriverTestBase.php
index 16041b4846..101930018e 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/WebDriverTestBase.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/WebDriverTestBase.php
@@ -95,7 +95,7 @@ protected function tearDown(): void {
     if ($this->mink) {
       // @todo ::getStatus was removed from PHPUnit 10, we probably need to
       // intercept an event instead.
-      if (RunnerVersion::getMajor < 10) {
+      if (RunnerVersion::getMajor() < 10) {
         $status = $this->getStatus();
         if ($status === BaseTestRunner::STATUS_ERROR || $status === BaseTestRunner::STATUS_WARNING || $status === BaseTestRunner::STATUS_FAILURE) {
           // Ensure we capture the output at point of failure.
diff --git a/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php
new file mode 100644
index 0000000000..2c732d14e3
--- /dev/null
+++ b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php
@@ -0,0 +1,104 @@
+<?php declare(strict_types=1);
+
+namespace Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging;
+
+use Drupal\Component\Utility\Html;
+use Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\Subscriber\TestRunnerFinishedSubscriber;
+use Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\Subscriber\TestRunnerStartedSubscriber;
+use PHPUnit\Event\Facade;
+use PHPUnit\Event\TestRunner\Finished as TestRunnerFinished;
+use PHPUnit\Event\TestRunner\Started as TestRunnerStarted;
+use PHPUnit\Util\Printer;
+
+/**
+ * @internal
+ */
+final class HtmlOutputLogger extends Printer
+{
+  /**
+   * File to write html links to.
+   *
+   * @var string
+   */
+  private string $browserOutputFile;
+
+  /**
+   * @throws \PHPUnit\Event\EventFacadeIsSealedException
+   * @throws \PHPUnit\Util\Exception
+   * @throws \PHPUnit\Event\UnknownSubscriberTypeException
+   */
+  public function __construct() {
+    Facade::registerSubscriber(new TestRunnerFinishedSubscriber($this));
+    Facade::registerSubscriber(new TestRunnerStartedSubscriber($this));
+  }
+
+  /**
+   * Creates the file to list the HTML output created during the test run.
+   *
+   * @see \Drupal\Tests\BrowserTestBase::initBrowserOutputFile()
+   */
+  public function testRunnerStarted(TestRunnerStarted $event): void {
+    $this->browserOutputFile = '';
+
+    if ($html_output_directory = getenv('BROWSERTEST_OUTPUT_DIRECTORY')) {
+      // Initialize html output debugging.
+      $html_output_directory = rtrim($html_output_directory, '/');
+
+      // Check if directory exists.
+      if (!is_dir($html_output_directory) || !is_writable($html_output_directory)) {
+        $this->writeWithColor('bg-red, fg-black', "HTML output directory $html_output_directory is not a writable directory.");
+      }
+      else {
+        // Convert to a canonicalized absolute pathname just in case the current
+        // working directory is changed.
+        $html_output_directory = realpath($html_output_directory);
+        $this->browserOutputFile = tempnam($html_output_directory, 'browser_output_');
+        if ($this->browserOutputFile) {
+          touch($this->browserOutputFile);
+        }
+        else {
+          $this->writeWithColor('bg-red, fg-black', "Unable to create a temporary file in $html_output_directory.");
+        }
+      }
+    }
+
+    if ($this->browserOutputFile !== '') {
+      putenv('BROWSERTEST_OUTPUT_FILE=' . $this->browserOutputFile);
+    }
+    else {
+      // Remove any environment variable.
+      putenv('BROWSERTEST_OUTPUT_FILE');
+    }
+  }
+
+  /**
+   * Prints the list of HTML output generated during the test.
+   */
+  public function testRunnerFinished(TestRunnerFinished $event): void {
+    if ($this->browserOutputFile !== '') {
+      $contents = file_get_contents($this->browserOutputFile);
+      if ($contents) {
+        $this->writeNewLine();
+        $this->writeWithColor('bg-yellow, fg-black', 'HTML output was generated');
+        $this->write($contents);
+      }
+      // No need to keep the file around any more.
+      unlink($this->browserOutputFile);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function write(string $buffer): void {
+    $buffer = Html::escape($buffer);
+    // Turn HTML output URLs into clickable link <a> tags.
+    $url_pattern = '@https?://[^\s]+@';
+    $buffer = preg_replace($url_pattern, '<a href="$0" target="_blank" title="$0">$0</a>', $buffer);
+    // Make the output readable in HTML by breaking up lines properly.
+    $buffer = nl2br($buffer);
+
+    print $buffer;
+  }
+
+}
diff --git a/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/Subscriber.php b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/Subscriber.php
new file mode 100644
index 0000000000..d2a29592b3
--- /dev/null
+++ b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/Subscriber.php
@@ -0,0 +1,22 @@
+<?php declare(strict_types=1);
+
+namespace Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\Subscriber;
+
+use Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\HtmlOutputLogger;
+
+/**
+ * @internal
+ */
+abstract class Subscriber
+{
+  private HtmlOutputLogger $logger;
+
+  public function __construct(HtmlOutputLogger $logger) {
+    $this->logger = $logger;
+  }
+
+  protected function logger(): HtmlOutputLogger {
+    return $this->logger;
+  }
+
+}
diff --git a/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/TestRunnerFinishedSubscriber.php b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/TestRunnerFinishedSubscriber.php
new file mode 100644
index 0000000000..2e870f2955
--- /dev/null
+++ b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/TestRunnerFinishedSubscriber.php
@@ -0,0 +1,16 @@
+<?php declare(strict_types=1);
+
+namespace Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\Subscriber;
+
+use PHPUnit\Event\TestRunner\Finished;
+use PHPUnit\Event\TestRunner\FinishedSubscriber;
+
+/**
+ * @internal
+ */
+final class TestRunnerFinishedSubscriber extends Subscriber implements FinishedSubscriber
+{
+  public function notify(Finished $event): void {
+    $this->logger()->testRunnerFinished($event);
+  }
+}
diff --git a/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/TestRunnerStartedSubscriber.php b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/TestRunnerStartedSubscriber.php
new file mode 100644
index 0000000000..503473bb63
--- /dev/null
+++ b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/Subscriber/TestRunnerStartedSubscriber.php
@@ -0,0 +1,16 @@
+<?php declare(strict_types=1);
+
+namespace Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\Subscriber;
+
+use PHPUnit\Event\TestRunner\Started;
+use PHPUnit\Event\TestRunner\StartedSubscriber;
+
+/**
+ * @internal
+ */
+final class TestRunnerStartedSubscriber extends Subscriber implements StartedSubscriber
+{
+  public function notify(Started $event): void {
+    $this->logger()->testRunnerStarted($event);
+  }
+}
diff --git a/core/tests/bootstrap.php b/core/tests/bootstrap.php
index 5f5b494cfc..2175c2efee 100644
--- a/core/tests/bootstrap.php
+++ b/core/tests/bootstrap.php
@@ -9,6 +9,8 @@
 
 use Drupal\Component\Assertion\Handle;
 use Drupal\TestTools\PhpUnitCompatibility\PhpUnit8\ClassWriter;
+use Drupal\TestTools\PhpUnitCompatibility\PhpUnit10\Logging\HtmlOutputLogger;
+use Drupal\TestTools\PhpUnitCompatibility\RunnerVersion;
 
 /**
  * Finds all valid extension directories recursively within a given directory.
@@ -179,3 +181,7 @@ class_alias('\Drupal\Tests\DocumentElement', '\Behat\Mink\Element\DocumentElemen
 // thrown if an assert fails, but this call does not turn runtime assertions on
 // if they weren't on already.
 Handle::register();
+
+if (RunnerVersion::getMajor() > 9) {
+  new HtmlOutputLogger();
+}