diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/VocabularyTest.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/VocabularyTest.php
index efc49c8..c7ec47d 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/VocabularyTest.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/VocabularyTest.php
@@ -90,7 +90,7 @@ function testTaxonomyAdminChangingWeights() {
     foreach ($vocabularies as $key => $vocabulary) {
       $weight = -$vocabulary->weight;
       $vocabularies[$key]->weight = $weight;
-      $edit['vocabularies[' . $key . '][weight]'] = $weight;
+      $edit['entities[' . $key . '][weight]'] = $weight;
     }
     // Saving the new weights via the interface.
     $this->drupalPost('admin/structure/taxonomy', $edit, t('Save'));