diff --git a/core/lib/Drupal/Core/Theme/ThemeInitialization.php b/core/lib/Drupal/Core/Theme/ThemeInitialization.php
index ee52887b59d12c3dca8a48c49aa5f86228f5fc1d..03f6b1ee29f4852b71f2752449496586dceb16dc 100644
--- a/core/lib/Drupal/Core/Theme/ThemeInitialization.php
+++ b/core/lib/Drupal/Core/Theme/ThemeInitialization.php
@@ -135,7 +135,7 @@ public function getActiveThemeByName($theme_name) {
    */
   public function loadActiveTheme(ActiveTheme $active_theme) {
     // Initialize the theme.
-    if ($theme_engine = $active_theme->getEngine()) {
+    if ($active_theme->getEngine()) {
       // Include the engine.
       include_once $this->root . '/' . $active_theme->getOwner();
       foreach ($active_theme->getBaseThemeExtensions() as $base) {