diff --git a/core/lib/Drupal/Core/Cache/MemoryBackend.php b/core/lib/Drupal/Core/Cache/MemoryBackend.php
index edda4d3..95c8458 100644
--- a/core/lib/Drupal/Core/Cache/MemoryBackend.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackend.php
@@ -73,15 +73,10 @@ public function getMultiple(&$cids, $allow_invalid = FALSE) {
    *   valid item to load.
    */
   protected function prepareItem($cache, $allow_invalid) {
-    if (!isset($cache->data)) {
+    if (!isset($cache['data'])) {
       return FALSE;
     }
-    // The object passed into this function is the one stored in $this->cache.
-    // We must clone it as part of the preparation step so that the actual
-    // cache object is not affected by the unserialize() call or other
-    // manipulations of the returned object.
-
-    $prepared = clone $cache;
+    $prepared = (object) $cache;
     $prepared->data = unserialize($prepared->data);
 
     // Check expire time.
@@ -102,7 +97,7 @@ public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = []) {
     $tags = array_unique($tags);
     // Sort the cache tags so that they are stored consistently in the database.
     sort($tags);
-    $this->cache[$cid] = (object) [
+    $this->cache[$cid] = [
       'cid' => $cid,
       'data' => serialize($data),
       'created' => $this->getRequestTime(),
@@ -146,7 +141,7 @@ public function deleteAll() {
    */
   public function invalidate($cid) {
     if (isset($this->cache[$cid])) {
-      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+      $this->cache[$cid]['expire'] = $this->getRequestTime() - 1;
     }
   }
 
@@ -156,7 +151,7 @@ public function invalidate($cid) {
   public function invalidateMultiple(array $cids) {
     foreach ($cids as $cid) {
       if (isset($this->cache[$cid])) {
-        $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+        $this->cache[$cid]['expire'] = $this->getRequestTime() - 1;
       }
     }
   }
@@ -166,8 +161,8 @@ public function invalidateMultiple(array $cids) {
    */
   public function invalidateTags(array $tags) {
     foreach ($this->cache as $cid => $item) {
-      if (array_intersect($tags, $item->tags)) {
-        $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+      if (array_intersect($tags, $item['tags'])) {
+        $this->cache[$cid]['expire'] = $this->getRequestTime() - 1;
       }
     }
   }
@@ -177,7 +172,7 @@ public function invalidateTags(array $tags) {
    */
   public function invalidateAll() {
     foreach ($this->cache as $cid => $item) {
-      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
+      $this->cache[$cid]['expire'] = $this->getRequestTime() - 1;
     }
   }