diff -u b/core/core.services.yml b/core/core.services.yml
--- b/core/core.services.yml
+++ b/core/core.services.yml
@@ -66,7 +66,7 @@
     arguments: ['@database', '@cache_tags.invalidator.checksum']
   cache.backend.apcu:
     class: Drupal\Core\Cache\ApcuBackendFactory
-    arguments: ['@app.root', '@kernel', '@cache_tags.invalidator.checksum']
+    arguments: ['@app.root', '@cache_tags.invalidator.checksum']
   cache.backend.php:
     class: Drupal\Core\Cache\PhpBackendFactory
     arguments: ['@cache_tags.invalidator.checksum']
@@ -136,7 +136,7 @@
     arguments: ['@database', '@cache_tags.invalidator.checksum']
   cache.backend.apcu:
     class: Drupal\Core\Cache\ApcuBackendFactory
-    arguments: ['@app.root', '@cache_tags.invalidator.checksum']
+    arguments: ['@app.root', '@site.path', '@cache_tags.invalidator.checksum']
   cache.backend.php:
     class: Drupal\Core\Cache\PhpBackendFactory
     arguments: ['@cache_tags.invalidator.checksum']
@@ -542,6 +542,16 @@
     class: Drupal\Core\AppRootFactory
     arguments: ['@kernel']
     public: false
+  site.path:
+    class: SplString
+    factory_service: 'site.path.factory'
+    factory_method: 'get'
+    tags:
+      - { name: parameter_service }
+  site.path.factory:
+    class: Drupal\Core\SitePathFactory
+    arguments: ['@kernel']
+    public: false
   controller_resolver:
     class: Drupal\Core\Controller\ControllerResolver
     arguments: ['@class_resolver']
diff -u b/core/lib/Drupal/Core/Cache/ApcuBackendFactory.php b/core/lib/Drupal/Core/Cache/ApcuBackendFactory.php
--- b/core/lib/Drupal/Core/Cache/ApcuBackendFactory.php
+++ b/core/lib/Drupal/Core/Cache/ApcuBackendFactory.php
@@ -20,13 +20,6 @@
   protected $sitePrefix;
 
   /**
-   * The Drupal kernel.
-   *
-   * @var \Drupal\Core\DrupalKernelInterface
-   */
-  protected $kernel;
-
-  /**
    * The cache tags checksum provider.
    *
    * @var \Drupal\Core\Cache\CacheTagsChecksumInterface
@@ -38,13 +31,13 @@
    *
    * @param string $root
    *   The app root.
-   * @param \Drupal\Core\DrupalKernelInterface $kernel
-   *   The Drupal kernel.
+   * @param string $site_path
+   *   The site path.
    * @param \Drupal\Core\Cache\CacheTagsChecksumInterface $checksum_provider
    *   The cache tags checksum provider.
    */
-  public function __construct($root, DrupalKernelInterface $kernel, CacheTagsChecksumInterface $checksum_provider) {
-    $this->sitePrefix = Crypt::hashBase64($root . '/' . $kernel->getSitePath());
+  public function __construct($root, $site_path, CacheTagsChecksumInterface $checksum_provider) {
+    $this->sitePrefix = Crypt::hashBase64($root . '/' . $site_path);
     $this->checksumProvider = $checksum_provider;
   }
 
only in patch2:
unchanged:
--- /dev/null
+++ b/core/lib/Drupal/Core/SitePathFactory.php
@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\SitePathFactory.
+ */
+
+namespace Drupal\Core;
+
+/**
+ * Gets the site path from the kernel.
+ */
+class SitePathFactory {
+
+  /**
+   * The Drupal kernel.
+   *
+   * @var \Drupal\Core\DrupalKernelInterface
+   */
+  protected $drupalKernel;
+
+  /**
+   * Constructs an SitePathFactory instance.
+   *
+   * @param \Drupal\Core\DrupalKernelInterface $drupal_kernel
+   *   The Drupal kernel.
+   */
+  public function __construct(DrupalKernelInterface $drupal_kernel) {
+    $this->drupalKernel = $drupal_kernel;
+  }
+
+  /**
+   * Gets the site path.
+   *
+   * @return string
+   *   The site path.
+   */
+  public function get() {
+    return $this->drupalKernel->getSitePath();
+  }
+
+}
+