diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
index d3098545cd..768fb742a9 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
@@ -335,6 +335,8 @@ protected function getExpectedUnauthorizedAccessMessage($method) {
         return "The 'access comments' permission is required and the comment must be published.";
       case 'POST';
         return "The 'post comments' permission is required.";
+      case 'PATCH';
+        return "The 'edit own comments' permission is required, the user must be the comment author, and the comment must be published.";
       default:
         return parent::getExpectedUnauthorizedAccessMessage($method);
     }