diff --git a/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php b/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php
index 997fd95..015eeb8 100644
--- a/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php
@@ -132,7 +132,7 @@ public function providerTestSortArrayOfLanguages() {
     $language10B->setId('ff');
 
     return array(
-      // Set up data set #1, already ordered by weight.
+      // Set up data set #0, already ordered by weight.
       array(
         // Set the data.
         array(
@@ -145,7 +145,7 @@ public function providerTestSortArrayOfLanguages() {
           $language10B->getId(),
         ),
       ),
-      // Set up data set #2, out of order by weight.
+      // Set up data set #1, out of order by weight.
       array(
         array(
           $language10B->getId() => $language10B,
@@ -156,7 +156,7 @@ public function providerTestSortArrayOfLanguages() {
           $language10B->getId(),
         ),
       ),
-      // Set up data set #3, tied by weight, already ordered by name.
+      // Set up data set #2, tied by weight, already ordered by name.
       array(
         array(
           $language10A->getId() => $language10A,
@@ -167,7 +167,7 @@ public function providerTestSortArrayOfLanguages() {
           $language10B->getId(),
         ),
       ),
-      // Set up data set #4, tied by weight, out of order by name.
+      // Set up data set #3, tied by weight, out of order by name.
       array(
         array(
           $language10B->getId() => $language10B,