diff --git a/core/lib/Drupal/Core/Test/TestRunnerKernel.php b/core/lib/Drupal/Core/Test/TestRunnerKernel.php
index 9fa7430c35acd7d854a2f2bb406ad03097b2cddb..0b2f790b8e3b6db65798f1f2bd7d681e4bd9a861 100644
--- a/core/lib/Drupal/Core/Test/TestRunnerKernel.php
+++ b/core/lib/Drupal/Core/Test/TestRunnerKernel.php
@@ -75,6 +75,9 @@ public function boot() {
 
     simpletest_classloader_register();
 
+    // Register stream wrappers.
+    $this->getContainer()->get('stream_wrapper_manager')->register();
+
     // Create the build/artifacts directory if necessary.
     if (!is_dir('public://simpletest')) {
       mkdir('public://simpletest', 0777, TRUE);