diff --git a/core/lib/Drupal/Component/Bridge/ZfExtensionManagerSfContainer.php b/core/lib/Drupal/Component/Bridge/ZfExtensionManagerSfContainer.php
index f914b698c8b5034448e3d43da2e3c5dad77e15d4..c6579465eeef008231dfe2aa09af64450362b8ae 100644
--- a/core/lib/Drupal/Component/Bridge/ZfExtensionManagerSfContainer.php
+++ b/core/lib/Drupal/Component/Bridge/ZfExtensionManagerSfContainer.php
@@ -55,7 +55,7 @@ class ZfExtensionManagerSfContainer implements ReaderManagerInterface, WriterMan
    *   The prefix to be used when retrieving plugins from the container.
    */
   public function __construct($prefix = '') {
-    return $this->prefix = $prefix;
+    $this->prefix = $prefix;
   }
 
   /**