diff --git a/core/lib/Drupal/Core/Cache/CacheCollector.php b/core/lib/Drupal/Core/Cache/CacheCollector.php
index b3c17fa..bbfd77e 100644
--- a/core/lib/Drupal/Core/Cache/CacheCollector.php
+++ b/core/lib/Drupal/Core/Cache/CacheCollector.php
@@ -195,7 +195,7 @@ protected function updateCache($lock = TRUE) {
     $lock_name = $this->cid . ':' . __CLASS__;
     if (!$lock || $this->lock->acquire($lock_name)) {
       if ($cached = $this->cache->get($this->cid)) {
-        $data = $cached->data + $data;
+        $data = array_merge($cached->data, $data);
       }
       // Remove keys marked for deletion.
       foreach ($this->keysToRemove as $delete_key) {
diff --git a/core/lib/Drupal/Core/KeyValueStore/KeyValueCacheDecorator.php b/core/lib/Drupal/Core/KeyValueStore/KeyValueCacheDecorator.php
index 49dab4b..2c09d7b 100644
--- a/core/lib/Drupal/Core/KeyValueStore/KeyValueCacheDecorator.php
+++ b/core/lib/Drupal/Core/KeyValueStore/KeyValueCacheDecorator.php
@@ -43,7 +43,7 @@ public function deleteMultiple(array $keys) {
     foreach ($keys as $key) {
       $this->delete($key);
     }
-    $this->keyValueStore->deleteMulitple($keys);
+    $this->keyValueStore->deleteMultiple($keys);
   }
 
   public function getAll() {
@@ -58,7 +58,7 @@ public function getCollectionName() {
   public function getMultiple(array $keys) {
     $values = array();
     foreach ($keys as $key) {
-      $values[$key] = $this->offsetGet($key);
+      $values[$key] = $this->get($key);
     }
     return $values;
   }