diff --git a/src/Plugin/facets/hierarchy/Taxonomy.php b/src/Plugin/facets/hierarchy/Taxonomy.php
index c4728ac..1f33838 100644
--- a/src/Plugin/facets/hierarchy/Taxonomy.php
+++ b/src/Plugin/facets/hierarchy/Taxonomy.php
@@ -2,8 +2,6 @@
 
 namespace Drupal\facets\Plugin\facets\hierarchy;
 
-use Drupal\Core\Database\Connection;
-use Drupal\Core\Database\Query\Condition;
 use Drupal\facets\Hierarchy\HierarchyPluginBase;
 use Drupal\taxonomy\Entity\Term;
 use Drupal\taxonomy\TermStorageInterface;
@@ -72,11 +70,15 @@ class Taxonomy extends HierarchyPluginBase {
    * {@inheritdoc}
    */
   public function getNestedChildIds($id) {
-    $children = &drupal_static(__FUNCTION__, []);
-    if (!isset($children[$id])) {
-      $term = Term::load($id)->getVocabularyId();
-      $children = $this->termStorage->loadTree($term, $id);
+    $children = $this->termStorage->loadChildren($id);
+    $subchilds = [];
+    $children = array_filter(array_values(array_map(function ($it) {
+      return $it->id();
+    }, $children)));
+    foreach ($children as $child) {
+      $subchilds = array_merge($subchilds, $this->getNestedChildIds($child));
     }
+    $children[$id] = array_merge($children, $subchilds);
     return isset($children[$id]) ? $children[$id] : [];
   }
 
@@ -105,16 +107,13 @@ class Taxonomy extends HierarchyPluginBase {
    *   Returns FALSE if no parent is found, else parent tid.
    */
   protected function taxonomyGetParent($tid) {
-    $parent = &drupal_static(__FUNCTION__, []);
     $parent = [];
 
-    if (!isset($parent[$tid])) {
-      $parents = $this->termStorage->loadParents($tid);
-      if (empty($parents)) {
-        return FALSE;
-      }
-      $parent[$tid] = reset($parents)->id();
+    $parents = $this->termStorage->loadParents($tid);
+    if (empty($parents)) {
+      return FALSE;
     }
+    $parent[$tid] = reset($parents)->id();
     return isset($parent[$tid]) ? $parent[$tid] : FALSE;
   }