.../tests/src/Unit/Render/BigPipeResponseAttachmentsProcessorTest.php  | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/core/modules/big_pipe/tests/src/Unit/Render/BigPipeResponseAttachmentsProcessorTest.php b/core/modules/big_pipe/tests/src/Unit/Render/BigPipeResponseAttachmentsProcessorTest.php
index 9123129..a3cfa3b 100644
--- a/core/modules/big_pipe/tests/src/Unit/Render/BigPipeResponseAttachmentsProcessorTest.php
+++ b/core/modules/big_pipe/tests/src/Unit/Render/BigPipeResponseAttachmentsProcessorTest.php
@@ -51,7 +51,8 @@ function nonHtmlResponseProvider() {
    * @dataProvider attachmentsProvider
    */
   public function testHtmlResponse(array $attachments) {
-    $big_pipe_response = new BigPipeResponse('original');
+    $big_pipe_response = new BigPipeResponse(TRUE, new HtmlResponse());
+    $big_pipe_response->setContent('original');
     $big_pipe_response->setAttachments($attachments);
 
     // This mock is the main expectation of this test: verify that the decorated