.../tests/src/Functional/EntityResource/EntityResourceTestBase.php     | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
index a7db61c..b12c4a1 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
@@ -246,8 +246,7 @@ public function testPost() {
 
     // DX: 415 when no Content-Type request header.
     $response = $this->request('POST', $url, $request_options);
-    // @todo update once https://www.drupal.org/node/2811133 lands.
-    $this->assertResourceErrorResponse(415, 'No route found that matches "Content-Type: "', $response);
+    $this->assertResourceErrorResponse(415, 'No "Content-Type" request header specified', $response);
 
 
     $request_options[RequestOptions::HEADERS]['Content-Type'] = static::$mimeType;