diff --git a/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php
index 9bc1a117b2..02162e9c83 100644
--- a/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php
+++ b/core/tests/Drupal/TestTools/PhpUnitCompatibility/PhpUnit10/Logging/HtmlOutputLogger.php
@@ -33,6 +33,7 @@
    * @throws \PHPUnit\Event\EventFacadeIsSealedException
    * @throws \PHPUnit\Util\Exception
    * @throws \PHPUnit\Event\UnknownSubscriberTypeException
+   * @throws \RuntimeException
    */
   private function __construct(string $browserTestOutputDirectory) {
     $this->browserOutputFile = $this->determineBrowserOutputFile($browserTestOutputDirectory);
@@ -47,6 +48,7 @@ private function __construct(string $browserTestOutputDirectory) {
    * @throws \PHPUnit\Event\EventFacadeIsSealedException
    * @throws \PHPUnit\Util\Exception
    * @throws \PHPUnit\Event\UnknownSubscriberTypeException
+   * @throws \RuntimeException
    */
   public static function init(string $browserTestOutputDirectory): void {
     if (self::$instance === NULL) {
@@ -57,9 +59,18 @@ public static function init(string $browserTestOutputDirectory): void {
   /**
    * @todo
    */
+  public static function isEnabled(): bool {
+    return self::$instance !== NULL;
+  }
+
+  /**
+   * @todo
+   *
+   * @throws \RuntimeException
+   */
   public static function log(string $logEntry): void {
-    if (self::$instance === NULL) {
-      return;
+    if (!self::isEnabled()) {
+      throw new \RuntimeException("HTML output is not enabled");
     }
     self::$instance->write($logEntry);
   }
@@ -69,13 +80,13 @@ public static function log(string $logEntry): void {
    */
   private function determineBrowserOutputFile(string $browserTestOutputDirectory): string {
     // Convert to a canonicalized absolute pathname just in case the current
-    // working directory is changed.
+    // working directory has changed.
     if (($html_output_directory = realpath(rtrim($browserTestOutputDirectory, '/'))) === FALSE) {
       throw new \RuntimeException("HTML output directory $browserTestOutputDirectory is not a writable directory");
     }
 
-    if (($browserOutputFile = tempnam($browserTestOutputDirectory, 'browser_output_')) === FALSE) {
-      throw new \RuntimeException("Unable to create a temporary file in $browserTestOutputDirectory");
+    if (($browserOutputFile = tempnam($html_output_directory, 'browser_output_')) === FALSE) {
+      throw new \RuntimeException("Unable to create a temporary file in $html_output_directory");
     }
 
     return $browserOutputFile;
diff --git a/core/tests/Drupal/Tests/BrowserHtmlDebugTrait.php b/core/tests/Drupal/Tests/BrowserHtmlDebugTrait.php
index c2d51fb797..22c1fb67a0 100644
--- a/core/tests/Drupal/Tests/BrowserHtmlDebugTrait.php
+++ b/core/tests/Drupal/Tests/BrowserHtmlDebugTrait.php
@@ -57,6 +57,8 @@
    * @var string
    *
    * @see \Drupal\Tests\Listeners\HtmlOutputPrinter
+   *
+   * @todo Remove when PHPUnit 9 is no longer supported.
    */
   protected $htmlOutputFile;
 
@@ -128,6 +130,7 @@ protected function htmlOutput($message = NULL) {
     // Do not use the file_url_generator service as the module_handler service
     // might not be available.
     $uri = $this->htmlOutputBaseUrl . '/sites/simpletest/browser_output/' . $html_output_filename;
+    // @todo Cleanup below when PHPUnit 9 is no longer supported.
     if (RunnerVersion::getMajor() > 9) {
       HtmlOutputLogger::log($uri . "\n");
     }
@@ -143,11 +146,19 @@ protected function htmlOutput($message = NULL) {
    * URLs to has been created by \Drupal\Tests\Listeners\HtmlOutputPrinter.
    */
   protected function initBrowserOutputFile() {
-    $browser_output_file = getenv('BROWSERTEST_OUTPUT_FILE');
-    $this->htmlOutputEnabled = is_file($browser_output_file);
+    // @todo Cleanup below when PHPUnit 9 is no longer supported.
+    if (RunnerVersion::getMajor() > 9) {
+      $this->htmlOutputEnabled = HtmlOutputLogger::isEnabled();
+    }
+    else {
+      $browser_output_file = getenv('BROWSERTEST_OUTPUT_FILE');
+      $this->htmlOutputEnabled = is_file($browser_output_file);
+      if ($this->htmlOutputEnabled) {
+        $this->htmlOutputFile = $browser_output_file;
+      }
+    }
     $this->htmlOutputBaseUrl = getenv('BROWSERTEST_OUTPUT_BASE_URL') ?: $GLOBALS['base_url'];
     if ($this->htmlOutputEnabled) {
-      $this->htmlOutputFile = $browser_output_file;
       $this->htmlOutputClassName = str_replace("\\", "_", static::class);
       $this->htmlOutputDirectory = DRUPAL_ROOT . '/sites/simpletest/browser_output';
       // Do not use the file_system service so this method can be called before