diff --git a/modules/simpletest/tests/taxonomy_test.install b/modules/simpletest/tests/taxonomy_test.install
index ae741f0e6fe3dba4552da9d6d48f712e323d0edf..2d771d0e22d8b5aff5e9325c85c72bb740f9ff67 100644
--- a/modules/simpletest/tests/taxonomy_test.install
+++ b/modules/simpletest/tests/taxonomy_test.install
@@ -10,14 +10,9 @@
  * Implement hook_schema().
  */
 function taxonomy_test_schema() {
-  $schema['term_antonym'] = array(
-    'description' => 'Stores term antonyms.',
+  $schema['taxonomy_term_antonym'] = array(
+    'description' => 'Stores term antonym.',
     'fields' => array(
-      'taid' => array(
-        'type' => 'serial',
-        'not null' => TRUE,
-        'description' => 'Primary Key: Unique term antonym ID.',
-      ),
       'tid' => array(
         'type' => 'int',
         'unsigned' => TRUE,
@@ -33,11 +28,7 @@ function taxonomy_test_schema() {
         'description' => 'The name of the antonym.',
       ),
     ),
-    'indexes' => array(
-      'tid' => array('tid'),
-      'name_tid' => array('name', 'tid'),
-    ),
-    'primary key' => array('taid'),
+    'primary key' => array('tid'),
   );
 
   return $schema;
diff --git a/modules/simpletest/tests/taxonomy_test.module b/modules/simpletest/tests/taxonomy_test.module
index beda61a5d12e5cfc5579f9e332c5b655b6cf2e68..536e5a100764363c22cc1d0f42e663f432acb7f3 100644
--- a/modules/simpletest/tests/taxonomy_test.module
+++ b/modules/simpletest/tests/taxonomy_test.module
@@ -11,7 +11,10 @@
  */
 function taxonomy_test_taxonomy_term_load(&$terms) {
   foreach ($terms as $term) {
-    $term->antonyms = taxonomy_test_get_antonyms($term->tid);
+    $antonym = taxonomy_test_get_antonym($term->tid);
+    if ($antonym) {
+      $term->antonym = $antonym;
+    }
   }
 }
 
@@ -19,17 +22,13 @@ function taxonomy_test_taxonomy_term_load(&$terms) {
  * Implement hook_taxonomy_term_insert().
  */
 function taxonomy_test_taxonomy_term_insert($term) {
-  if (!empty($term->antonyms)) {
-    foreach (explode ("\n", str_replace("\r", '', $term->antonyms)) as $antonym) {
-      if ($antonym) {
-        db_insert('term_antonym')
-          ->fields(array(
-            'tid' => $term->tid,
-            'name' => rtrim($antonym),
-          ))
-          ->execute();
-      }
-    }
+  if (!empty($term->antonym)) {
+    db_insert('taxonomy_term_antonym')
+      ->fields(array(
+        'tid' => $term->tid,
+        'name' => trim($term->antonym)
+      ))
+      ->execute();
   }
 }
 
@@ -37,18 +36,13 @@ function taxonomy_test_taxonomy_term_insert($term) {
  * Implement hook_taxonomy_term_update().
  */
 function taxonomy_test_taxonomy_term_update($term) {
-  taxonomy_test_taxonomy_term_delete($term);
-  if (!empty($term->antonyms)) {
-    foreach (explode ("\n", str_replace("\r", '', $term->antonyms)) as $antonym) {
-      if ($antonym) {
-        db_insert('term_antonym')
-          ->fields(array(
-            'tid' => $term->tid,
-            'name' => rtrim($antonym),
-          ))
-          ->execute();
-      }
-    }
+  if (!empty($term->antonym)) {
+    db_merge('taxonomy_term_antonym')
+      ->key(array('tid' => $term->tid))
+      ->fields(array(
+        'name' => trim($term->antonym)
+      ))
+      ->execute();
   }
 }
 
@@ -56,7 +50,7 @@ function taxonomy_test_taxonomy_term_update($term) {
  * Implement hook_taxonomy_term_delete().
  */
 function taxonomy_test_taxonomy_term_delete($term) {
-  db_delete('term_antonym')
+  db_delete('taxonomy_term_antonym')
     ->condition('tid', $term->tid)
     ->execute();
 }
@@ -66,29 +60,23 @@ function taxonomy_test_taxonomy_term_delete($term) {
  */
 function taxonomy_test_form_alter(&$form, $form_state, $form_id) {
   if ($form_id == 'taxonomy_form_term') {
-    $antonyms = taxonomy_test_get_antonyms($form['#term']['tid']);
-    $form['advanced']['antonyms'] = array(
-      '#type' => 'textarea',
-      '#title' => t('Antonyms'),
-      '#default_value' => !empty($antonyms) ? implode("\n", $antonyms) : NULL,
-      '#description' => t('Antonyms of this term, one antonym per line.')
+    $antonym = taxonomy_test_get_antonym($form['#term']['tid']);
+    $form['advanced']['antonym'] = array(
+      '#type' => 'textfield',
+      '#title' => t('Antonym'),
+      '#default_value' => !empty($antonym) ? $antonym : '',
+      '#description' => t('Antonym of this term.')
     );
   }
 }
 
 /**
- * Return an array of antonyms of the given term ID.
+ * Return the antonym of the given term ID.
  */
-function taxonomy_test_get_antonyms($tid) {
-  if ($tid) {
-    $antonyms = array();
-    $result = db_query('SELECT name FROM {term_antonym} WHERE tid = :tid', array(':tid' => $tid));
-    foreach($result as $antonym) {
-      $antonyms[] = $antonym->name;
-    }
-    return $antonyms;
-  }
-  else {
-    return FALSE;
-  }
+function taxonomy_test_get_antonym($tid) {
+  return db_select('taxonomy_term_antonym', 'ta')
+    ->fields('ta', array('name'))
+    ->condition('tid', $tid)
+    ->execute()
+    ->fetchField();
 }
diff --git a/modules/taxonomy/taxonomy.test b/modules/taxonomy/taxonomy.test
index 8c97a1f9675d040d62c97665ef451ce4ae258886..89e3912db4415ccb4ad6ce2dd97d12089e63f068 100644
--- a/modules/taxonomy/taxonomy.test
+++ b/modules/taxonomy/taxonomy.test
@@ -705,26 +705,26 @@ class TaxonomyHooksTestCase extends TaxonomyWebTestCase {
     // Create a term with one antonym.
     $edit = array(
       'name' => $this->randomName(),
-      'antonyms' => 'Long',
+      'antonym' => 'Long',
     );
     $this->drupalPost('admin/structure/taxonomy/' . $vocabulary->vid . '/add', $edit, t('Save'));
     $term = reset(taxonomy_get_term_by_name($edit['name']));
-    $this->assertEqual($term->antonyms[0], $edit['antonyms'], t('Antonyms were loaded into the term object'));
+    $this->assertEqual($term->antonym, $edit['antonym'], t('Antonym was loaded into the term object'));
 
     // Update the term with a different antonym.
     $edit = array(
       'name' => $this->randomName(),
-      'antonyms' => 'Short',
+      'antonym' => 'Short',
     );
     $this->drupalPost('taxonomy/term/' . $term->tid . '/edit', $edit, t('Save'));
     taxonomy_terms_static_reset();
     $term = taxonomy_term_load($term->tid);
-    $this->assertTrue(in_array($edit['antonyms'], $term->antonyms), t('Antonym was successfully edited'));
+    $this->assertEqual($edit['antonym'], $term->antonym, t('Antonym was successfully edited'));
 
     // Delete the term.
     taxonomy_term_delete($term->tid);
-    $antonyms = db_query('SELECT taid FROM {term_antonym} WHERE tid = :tid', array(':tid' => $term->tid))->fetchField();
-    $this->assertFalse($antonyms, t('The antonyms were deleted from the database.'));
+    $antonym = db_query('SELECT tid FROM {taxonomy_term_antonym} WHERE tid = :tid', array(':tid' => $term->tid))->fetchField();
+    $this->assertFalse($antonym, t('The antonym were deleted from the database.'));
   }
 }