diff --git a/core/includes/common.inc b/core/includes/common.inc
index 7f774cff22df3a25d5b2b55537157ce4aef251c9..f8f669772cd398101902ad0ffc61a361c3afa03e 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -2524,21 +2524,6 @@ function drupal_json_decode($var) {
   return Json::decode($var);
 }
 
-/**
- * Ensures the private key variable used to generate tokens is set.
- *
- * @return string
- *   The private key.
- *
- * @see \Drupal\Core\Access\CsrfTokenGenerator
- *
- * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
- *   Use \Drupal::service('private_key')->get().
- */
-function drupal_get_private_key() {
-  return \Drupal::service('private_key')->get();
-}
-
 /**
  * Generates a token based on $value, the user session, and the private key.
  *
diff --git a/core/modules/simpletest/src/WebTestBase.php b/core/modules/simpletest/src/WebTestBase.php
index f0c52571b1aa2dc1aeff09edfb1e32295a579597..351c84be3259f5df17b3b536e0d1c7469c81c7c6 100644
--- a/core/modules/simpletest/src/WebTestBase.php
+++ b/core/modules/simpletest/src/WebTestBase.php
@@ -759,7 +759,7 @@ protected function drupalUserIsLoggedIn($account) {
    * Generate a token for the currently logged in user.
    */
   protected function drupalGetToken($value = '') {
-    $private_key = drupal_get_private_key();
+    $private_key = \Drupal::service('private_key')->get();
     return Crypt::hmacBase64($value, $this->session_id . $private_key);
   }