diff --git a/core/modules/forum/src/Form/ForumForm.php b/core/modules/forum/src/Form/ForumForm.php
index 1a517c0..3f7b8e9 100644
--- a/core/modules/forum/src/Form/ForumForm.php
+++ b/core/modules/forum/src/Form/ForumForm.php
@@ -129,14 +129,8 @@ protected function actions(array $form, FormStateInterface $form_state) {
    */
   protected function forumParentSelect($tid, $title) {
     $taxonomy_storage = $this->entityManager->getStorage('taxonomy_term');
-    $parents = $taxonomy_storage->loadParents($tid);
-    if ($parents) {
-      $parent = array_shift($parents);
-      $parent = $parent->id();
-    }
-    else {
-      $parent = 0;
-    }
+    $parents = array_keys($taxonomy_storage->loadParents($tid));
+    $parent = reset($parents);
 
     $vid = $this->config('forum.settings')->get('vocabulary');
     $children = $taxonomy_storage->loadTree($vid, $tid, NULL, TRUE);
diff --git a/core/modules/taxonomy/src/TermStorage.php b/core/modules/taxonomy/src/TermStorage.php
index 38ca761..b844a32 100644
--- a/core/modules/taxonomy/src/TermStorage.php
+++ b/core/modules/taxonomy/src/TermStorage.php
@@ -126,23 +126,26 @@ public function updateTermHierarchy(EntityInterface $term) {
   public function loadParents($tid) {
     if (!isset($this->parents[$tid])) {
       $parents = array();
-      $query = $this->database->select('taxonomy_term_field_data', 't');
-      $query->join('taxonomy_term_hierarchy', 'h', 'h.parent = t.tid');
-      $query->addField('t', 'tid');
+      $query = $this->database->select('taxonomy_term_hierarchy', 'h');
+      $query->leftJoin('taxonomy_term_field_data', 't', 'h.parent = t.tid');
+      $query->addField('h', 'parent');
       $query->condition('h.tid', $tid);
-      $query->condition('t.default_langcode', 1);
+      $query->condition($query->orConditionGroup()
+        ->condition('h.parent', 0)
+        ->condition('t.default_langcode', 1)
+      );
       $query->addTag('term_access');
       $query->orderBy('t.weight');
       $query->orderBy('t.name');
       $ids = $query->execute()->fetchCol();
       if ($ids) {
-        // If there is a <root> parent in the list, it will be filtered out in
-        // loadMultiple() because there's no entity associated with the <root>.
-        // In this case, the parent is added with key 0 and NULL.
-        if (in_array(0, $ids)) {
-          $parents[0] = NULL;
+        $terms = $this->loadMultiple($ids);
+        foreach ($ids as $id) {
+          // The <root> parent was filtered out in loadMultiple() because
+          // there's no entity associated with <root>. In this case, the parent
+          // is re-added with key 0 and NULL.
+          $parents[$id] = $id != 0 ? $terms[$id] : NULL;
         }
-        $parents += $this->loadMultiple($ids);
       }
       $this->parents[$tid] = $parents;
     }
diff --git a/core/modules/taxonomy/src/Tests/Migrate/d7/MigrateTaxonomyTermTest.php b/core/modules/taxonomy/src/Tests/Migrate/d7/MigrateTaxonomyTermTest.php
index 6c01697..8937141 100644
--- a/core/modules/taxonomy/src/Tests/Migrate/d7/MigrateTaxonomyTermTest.php
+++ b/core/modules/taxonomy/src/Tests/Migrate/d7/MigrateTaxonomyTermTest.php
@@ -61,12 +61,12 @@ protected function assertEntity($id, $expected_label, $expected_vid, $expected_d
    * Tests the Drupal 7 taxonomy term to Drupal 8 migration.
    */
   public function testTaxonomyTerms() {
-    $this->assertEntity(1, 'General discussion', 'forums', '', 2);
-    $this->assertEntity(2, 'Term1', 'test_vocabulary', 'The first term.');
-    $this->assertEntity(3, 'Term2', 'test_vocabulary', 'The second term.');
+    $this->assertEntity(1, 'General discussion', 'forums', '', 2, [0]);
+    $this->assertEntity(2, 'Term1', 'test_vocabulary', 'The first term.', 0, [0]);
+    $this->assertEntity(3, 'Term2', 'test_vocabulary', 'The second term.', 0, [0]);
     $this->assertEntity(4, 'Term3', 'test_vocabulary', 'The third term.', 0, [3]);
-    $this->assertEntity(5, 'Custom Forum', 'forums', 'Where the cool kids are.', 3);
-    $this->assertEntity(6, 'Games', 'forums', '', 4);
+    $this->assertEntity(5, 'Custom Forum', 'forums', 'Where the cool kids are.', 3, [0]);
+    $this->assertEntity(6, 'Games', 'forums', '', 4, [0]);
     $this->assertEntity(7, 'Minecraft', 'forums', '', 1, [6]);
     $this->assertEntity(8, 'Half Life 3', 'forums', '', 0, [6]);
   }
diff --git a/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php b/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
index 322c92b..d3f7355 100644
--- a/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
+++ b/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
@@ -74,10 +74,10 @@ function testTermIndentation() {
     // All terms back at the root level, no indentation should be present.
     $this->assertNoPattern('|<div class="js-indentation indentation">&nbsp;</div>|');
 
-    // Check explicitly that term 2 has no parents.
+    // Check explicitly that term 2 has no other parents than the <root> parent.
     \Drupal::entityManager()->getStorage('taxonomy_term')->resetCache();
     $parents = $taxonomy_storage->loadParents($term2->id());
-    $this->assertTrue(empty($parents), 'Term 2 has no parents now');
+    $this->assertIdentical($parents, array(0 => NULL));
   }
 
 }
diff --git a/core/modules/taxonomy/src/Tests/TermTest.php b/core/modules/taxonomy/src/Tests/TermTest.php
index 9d06719..f9d4daf 100644
--- a/core/modules/taxonomy/src/Tests/TermTest.php
+++ b/core/modules/taxonomy/src/Tests/TermTest.php
@@ -458,7 +458,9 @@ function testTermMultipleParentsInterface() {
     // Check that the parent tid is still there. The other parent (<root>) is
     // not added by \Drupal\taxonomy\TermStorageInterface::loadParents().
     $parents = $this->container->get('entity.manager')->getStorage('taxonomy_term')->loadParents($term->id());
-    $parent = reset($parents);
+    $parent = key($parents);
+    $this->assertEqual($edit['parent[]'][0], $parent);
+    $parent = $parents[1];
     $this->assertEqual($edit['parent[]'][1], $parent->id(), 'Term parents were successfully saved.');
   }