diff --git a/core/modules/forum/src/Tests/ForumTest.php b/core/modules/forum/src/Tests/ForumTest.php
index 9bf3e0932a..f04d17a8ff 100644
--- a/core/modules/forum/src/Tests/ForumTest.php
+++ b/core/modules/forum/src/Tests/ForumTest.php
@@ -401,14 +401,16 @@ function editForumVocabulary() {
    */
   function createForum($type, $parent = 0) {
     // Generate a random name/description.
-    $name = 'f' . $this->randomMachineName(10);
+    $name = $this->randomMachineName(10);
     $description = $this->randomMachineName(100);
 
+    // Weight is set to -1, in order to have new added Forum as first in list,
+    // because that's expected by tests that use this method.
     $edit = array(
       'name[0][value]' => $name,
       'description[0][value]' => $description,
       'parent[0]' => $parent,
-      'weight' => '0',
+      'weight' => '-1',
     );
 
     // Create forum.