diff --git a/core/lib/Drupal/Core/EventSubscriber/DefaultExceptionSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/DefaultExceptionSubscriber.php
index 15c1f07..594075b 100644
--- a/core/lib/Drupal/Core/EventSubscriber/DefaultExceptionSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/DefaultExceptionSubscriber.php
@@ -87,7 +87,6 @@ protected function getErrorLevel() {
   protected function onHtml(GetResponseForExceptionEvent $event) {
     $exception = $event->getException();
     $error = Error::decodeException($exception);
-    $flatten_exception = $exception;
 
     // Display the message if the current error reporting level allows this type
     // of message to be displayed, and unconditionally in update.php.
@@ -114,7 +113,7 @@ protected function onHtml(GetResponseForExceptionEvent $event) {
 
       // Check if verbose error reporting is on.
       if ($this->getErrorLevel() == ERROR_REPORTING_DISPLAY_VERBOSE) {
-        $backtrace_exception = $flatten_exception;
+        $backtrace_exception = $exception;
         while ($backtrace_exception->getPrevious()) {
           $backtrace_exception = $backtrace_exception->getPrevious();
         }