diff --git a/core/lib/Drupal/Core/Cache/CacheCollector.php b/core/lib/Drupal/Core/Cache/CacheCollector.php
index 7ecbd6d..afc6922 100644
--- a/core/lib/Drupal/Core/Cache/CacheCollector.php
+++ b/core/lib/Drupal/Core/Cache/CacheCollector.php
@@ -220,7 +220,6 @@ protected function updateCache($lock = TRUE) {
     }
 
     // Lock cache writes to help avoid stampedes.
-    // To implement locking for cache misses, override __construct().
     $lock_name = $this->cid . ':' . __CLASS__;
     if (!$lock || $this->lock->acquire($lock_name)) {
       // Set and delete operations invalidate the cache item. Try to also load
@@ -268,7 +267,12 @@ public function reset() {
    */
   public function clear() {
     $this->reset();
-    $this->cache->delete($this->cid);
+    if ($this->tags) {
+      $this->cache->deleteTags($this->tags);
+    }
+    else {
+      $this->cache->delete($this->cid);
+    }
   }
 
   /**
diff --git a/core/modules/locale/tests/Drupal/locale/Tests/LocaleTranslationTest.php b/core/modules/locale/tests/Drupal/locale/Tests/LocaleTranslationTest.php
index c400400..f66024e 100644
--- a/core/modules/locale/tests/Drupal/locale/Tests/LocaleTranslationTest.php
+++ b/core/modules/locale/tests/Drupal/locale/Tests/LocaleTranslationTest.php
@@ -38,13 +38,15 @@ public static function getInfo() {
    */
   protected function setUp() {
     $this->storage = $this->getMock('Drupal\locale\StringStorageInterface');
+    $this->cache = $this->getMock('Drupal\Core\Cache\CacheBackendInterface');
+    $this->lock = $this->getMock('Drupal\Core\Lock\LockBackendInterface');
   }
 
   /**
    * Tests for \Drupal\locale\LocaleTranslation::destruct()
    */
   public function testDestruct() {
-    $translation = new LocaleTranslation($this->storage);
+    $translation = new LocaleTranslation($this->storage, $this->cache, $this->lock);
     // Prove that destruction works without errors when translations are empty.
     $this->assertAttributeEmpty('translations', $translation);
     $translation->destruct();
diff --git a/core/tests/Drupal/Tests/Core/Cache/CacheCollectorTest.php b/core/tests/Drupal/Tests/Core/Cache/CacheCollectorTest.php
index c3cc755..702c7c7 100644
--- a/core/tests/Drupal/Tests/Core/Cache/CacheCollectorTest.php
+++ b/core/tests/Drupal/Tests/Core/Cache/CacheCollectorTest.php
@@ -105,6 +105,12 @@ public function testSetAndGetNull() {
     $this->collector->set($key, $value);
     $this->assertTrue($this->collector->has($key));
     $this->assertEquals($value, $this->collector->get($key));
+
+    // Ensure that getting a value that isn't set does not mark it as
+    // existent.
+    $non_existing_key = $this->randomName(7);
+    $this->collector->get($non_existing_key);
+    $this->assertFalse($this->collector->has($non_existing_key));
   }
 
   /**
@@ -152,7 +158,6 @@ public function testDelete() {
    * Tests updating the cache when no changes were made.
    */
   public function testUpdateCacheNoChanges() {
-
     $this->lock->expects($this->never())
       ->method('acquire');
     $this->cache->expects($this->never())
@@ -217,7 +222,7 @@ public function testUpdateCacheLockFail() {
   }
 
   /**
-   * Tests updating the cache when there is a
+   * Tests updating the cache when there is a conflict after cache invalidation.
    */
   public function testUpdateCacheInvalidatedConflict() {
     $key = $this->randomName();
@@ -380,6 +385,36 @@ public function testUpdateCacheClear() {
     $this->cache->expects($this->once())
       ->method('delete')
       ->with($this->cid);
+    $this->cache->expects($this->never())
+      ->method('deleteTags');
+    $this->collector->clear();
+    $this->assertEquals($value, $this->collector->get($key));
+    $this->assertEquals(2, $this->collector->getCacheMisses());
+  }
+
+  /**
+   * Tests a clear of the cache collector using tags.
+   */
+  public function testUpdateCacheClearTags() {
+    $key = $this->randomName();
+    $value = $this->randomName();
+    $tags = array($this->randomName() => TRUE);
+    $this->collector = new CacheCollectorHelper($this->cid, $this->cache, $this->lock, $tags);
+
+    // Set the data and request it.
+    $this->collector->setCacheMissData($key, $value);
+    $this->assertEquals($value, $this->collector->get($key));
+    $this->assertEquals($value, $this->collector->get($key));
+
+    // Should have been added to the storage and only be requested once.
+    $this->assertEquals(1, $this->collector->getCacheMisses());
+
+    // Clear the collected cache using the tags, should call it again.
+    $this->cache->expects($this->never())
+      ->method('delete');
+    $this->cache->expects($this->once())
+      ->method('deleteTags')
+      ->with($tags);
     $this->collector->clear();
     $this->assertEquals($value, $this->collector->get($key));
     $this->assertEquals(2, $this->collector->getCacheMisses());