diff -u b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTranslationTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTranslationTest.php
--- b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTranslationTest.php
@@ -24,7 +24,7 @@
     $tests = [];
 
     // The source data.
-    $tests[0][0]['i18n_string'] = [
+    $tests[0]['source_data']['i18n_string'] = [
       [
         'lid' => '1',
         'textgroup' => 'taxonomy',
@@ -57,7 +57,7 @@
       ],
     ];
 
-    $tests[0][0]['locales_target'] = [
+    $tests[0]['source_data']['locales_target'] = [
       [
         'lid' => 1,
         'language' => 'fr',
@@ -84,7 +84,7 @@
       ],
     ];
 
-    $tests[0][0]['taxonomy_vocabulary'] = [
+    $tests[0]['source_data']['taxonomy_vocabulary'] = [
       [
         'vid' => 1,
         'name' => 'vocabulary 1',
@@ -126,12 +126,12 @@
         'objectid' => '1',
         'lt_lid' => '1',
         'translation' => 'fr - vocabulary 1',
-        'language' => 'fr',
+        'v_language' => 'und',
         'textgroup' => 'taxonomy',
         'context' => 'vocabulary:1:name',
         'objectindex' => '1',
         'format' => '',
-        'ltlanguage' => 'fr',
+        'language' => 'fr',
         'plid' => '0',
         'plural' => '0',
         'i18n_status' => '0',
@@ -151,17 +151,29 @@
         'objectid' => '1',
         'lt_lid' => '2',
         'translation' => 'fr - description of vocabulary 1',
-        'language' => 'fr',
+        'v_language' => 'und',
         'textgroup' => 'taxonomy',
         'context' => 'vocabulary:1:description',
         'objectindex' => '1',
         'format' => '',
-        'ltlanguage' => 'fr',
+        'language' => 'fr',
         'plid' => '0',
         'plural' => '0',
         'i18n_status' => '0',
       ],
     ];
+
+    $tests[1] = $tests[0];
+
+    // Test without the language and i18n_mode columns in taxonomy_vocabulary.
+    foreach ($tests[1]['source_data']['taxonomy_vocabulary'] as &$data) {
+      unset($data['language']);
+      unset($data['i18n_mode']);
+    }
+    foreach ($tests[1]['expected_results'] as &$data) {
+      unset($data['v_language']);
+      unset($data['i18n_mode']);
+    }
     return $tests;
   }