diff --git a/core/lib/Drupal/Core/StringTranslation/TranslationManager.php b/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
index b465983..fce0311 100644
--- a/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
+++ b/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
@@ -19,11 +19,24 @@ class TranslationManager implements TranslatorInterface {
    * An array of active translators keyed by priority.
    *
    * @var array
-   *   Array of Drupal\Core\Translation\Translator\TranslatorInterface objects
+   *   Array of \Drupal\Core\Translation\Translator\TranslatorInterface objects
    */
   protected $translators = array();
 
   /**
+   * Holds the array of translators sorted by priority.
+   *
+   * If this is NULL a rebuild will be triggered.
+   *
+   * @var array
+   *   An array of path processor objects.
+   *
+   * @see \Drupal\Core\StringTranslation\TranslationManager::addTranslator()
+   * @see \Drupal\Core\StringTranslation\TranslationManager::sortTranslators()
+   */
+  protected $sortedTranslators = NULL;
+
+  /**
    * The default langcode used in translations.
    *
    * @var string
@@ -52,7 +65,8 @@ public function __construct() {
    */
   public function addTranslator(TranslatorInterface $translator, $priority = 0) {
     $this->translators[$priority][] = $translator;
-
+    // Reset sorted translators property to trigger rebuild.
+    $this->sortedTranslators = NULL;
     return $this;
   }
 
@@ -76,7 +90,10 @@ protected function sortTranslators() {
    * {@inheritdoc}
    */
   public function getStringTranslation($langcode, $string, $context) {
-    foreach ($this->sortTranslators() as $translator) {
+    if ($this->sortedTranslators === NULL) {
+      $this->sortedTranslators = $this->sortTranslators();
+    }
+    foreach ($this->sortedTranslators as $translator) {
       $translation = $translator->getStringTranslation($langcode, $string, $context);
       if ($translation !== FALSE) {
         return $translation;
@@ -140,7 +157,10 @@ public function setDefaultLangcode($langcode) {
    * {@inheritdoc}
    */
   public function reset() {
-    foreach ($this->sortTranslators() as $translator) {
+    if ($this->sortedTranslators === NULL) {
+      $this->sortedTranslators = $this->sortTranslators();
+    }
+    foreach ($this->sortedTranslators as $translator) {
       $translator->reset();
     }
   }