core/modules/block/src/BlockViewBuilder.php                 |  2 +-
 core/modules/block/src/Tests/BlockViewBuilderTest.php       | 13 ++++++++-----
 .../block/tests/modules/block_test/block_test.module        |  3 ++-
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/core/modules/block/src/BlockViewBuilder.php b/core/modules/block/src/BlockViewBuilder.php
index 9d1fa80..c3d6147 100644
--- a/core/modules/block/src/BlockViewBuilder.php
+++ b/core/modules/block/src/BlockViewBuilder.php
@@ -75,7 +75,7 @@ public function viewMultiple(array $entities = array(), $view_mode = 'full', $la
         $this->getCacheTag(), // Block view builder cache tag.
         $entity->getCacheTag(), // Block entity cache tag.
         $entity->getListCacheTags(), // Block entity list cache tags.
-        $plugin->getCacheTags(), // Block plugin cache tags.
+        $plugin->getCacheTags() // Block plugin cache tags.
       );
 
       if ($plugin->isCacheable()) {
diff --git a/core/modules/block/src/Tests/BlockViewBuilderTest.php b/core/modules/block/src/Tests/BlockViewBuilderTest.php
index c9b1583..a115c6d 100644
--- a/core/modules/block/src/Tests/BlockViewBuilderTest.php
+++ b/core/modules/block/src/Tests/BlockViewBuilderTest.php
@@ -9,6 +9,7 @@
 
 use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\UrlCacheContext;
 use Drupal\simpletest\DrupalUnitTestBase;
 use Symfony\Component\HttpFoundation\Request;
@@ -236,22 +237,24 @@ public function testBlockViewBuilderAlter() {
     $this->assertIdentical(drupal_render($build), '');
     $cache_entry = $this->container->get('cache.render')->get($cid);
     $this->assertTrue($cache_entry, 'The block render element has been cached with the expected cache ID.');
-    $expected_flattened_tags = array('block_view:1', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', 'rendered:1');
-    $this->assertIdentical($cache_entry->tags, $expected_flattened_tags, 'The block render element has been cached with the expected cache tags.');
+    $expected_tags = array('block_view', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', 'rendered');
+    sort($expected_tags);
+    $this->assertIdentical($cache_entry->tags, $expected_tags, 'The block render element has been cached with the expected cache tags.');
     $this->container->get('cache.render')->delete($cid);
 
     // Advanced: cached block, but an alter hook adds an additional cache tag.
     $alter_add_tag = $this->randomMachineName();
     \Drupal::state()->set('block_test_view_alter_cache_tag', $alter_add_tag);
-    $expected_tags = NestedArray::mergeDeep($default_tags, array($alter_add_tag => TRUE));
+    $expected_tags = Cache::mergeTags($default_tags, array($alter_add_tag));
     $build = $this->getBlockRenderArray();
     $this->assertIdentical($expected_tags, $build['#cache']['tags'], 'An altered cacheable block has the expected cache tags.');
     $cid = drupal_render_cid_create(array('#cache' => array('keys' => $expected_keys)));
     $this->assertIdentical(drupal_render($build), '');
     $cache_entry = $this->container->get('cache.render')->get($cid);
     $this->assertTrue($cache_entry, 'The block render element has been cached with the expected cache ID.');
-    $expected_flattened_tags = array('block_view:1', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', $alter_add_tag . ':1', 'rendered:1');
-    $this->assertIdentical($cache_entry->tags, $expected_flattened_tags, 'The block render element has been cached with the expected cache tags.');
+    $expected_tags = array('block_view', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', $alter_add_tag, 'rendered');
+    sort($expected_tags);
+    $this->assertIdentical($cache_entry->tags, $expected_tags, 'The block render element has been cached with the expected cache tags.');
     $this->container->get('cache.render')->delete($cid);
 
     // Advanced: cached block, but an alter hook adds a #pre_render callback to
diff --git a/core/modules/block/tests/modules/block_test/block_test.module b/core/modules/block/tests/modules/block_test/block_test.module
index d4bf97f..19e65ad 100644
--- a/core/modules/block/tests/modules/block_test/block_test.module
+++ b/core/modules/block/tests/modules/block_test/block_test.module
@@ -6,6 +6,7 @@
  */
 
 use Drupal\Core\Block\BlockPluginInterface;
+use Drupal\Core\Cache\Cache;
 
 /**
  * Implements hook_block_alter().
@@ -27,7 +28,7 @@ function block_test_block_view_test_cache_alter(array &$build, BlockPluginInterf
     $build['#cache']['keys'][] = \Drupal::state()->get('block_test_view_alter_cache_key');
   }
   if (\Drupal::state()->get('block_test_view_alter_cache_tag') !== NULL) {
-    $build['#cache']['tags'][\Drupal::state()->get('block_test_view_alter_cache_tag')] = TRUE;
+    $build['#cache']['tags'] = Cache::mergeTags($build['#cache']['tags'], [\Drupal::state()->get('block_test_view_alter_cache_tag')]);
   }
   if (\Drupal::state()->get('block_test_view_alter_append_pre_render_prefix') !== NULL) {
     $build['#pre_render'][] = 'block_test_pre_render_alter_content';