diff --git a/core/modules/system/src/Tests/Cache/ApcuBackendUnitTest.php b/core/modules/system/src/Tests/Cache/ApcuBackendUnitTest.php
index da8f565..c10f25a 100644
--- a/core/modules/system/src/Tests/Cache/ApcuBackendUnitTest.php
+++ b/core/modules/system/src/Tests/Cache/ApcuBackendUnitTest.php
@@ -34,7 +34,9 @@ protected function checkRequirements() {
   }
 
   protected function createCacheBackend($bin) {
-    return new ApcuBackend($bin, $this->databasePrefix);
+    $backend = new ApcuBackend($bin, $this->databasePrefix);
+    \Drupal::service('cache_tags')->addHandler($backend);
+    return $backend;
   }
 
   protected function tearDown() {
diff --git a/core/modules/system/src/Tests/Cache/BackendChainUnitTest.php b/core/modules/system/src/Tests/Cache/BackendChainUnitTest.php
index cbfaf16..cc5760b 100644
--- a/core/modules/system/src/Tests/Cache/BackendChainUnitTest.php
+++ b/core/modules/system/src/Tests/Cache/BackendChainUnitTest.php
@@ -26,6 +26,8 @@ protected function createCacheBackend($bin) {
       ->prependBackend(new MemoryBackend('bar'))
       ->appendBackend(new MemoryBackend('baz'));
 
+    \Drupal::service('cache_tags')->addHandler($chain);
+
     return $chain;
   }
 }
diff --git a/core/modules/system/src/Tests/Cache/GenericCacheBackendUnitTestBase.php b/core/modules/system/src/Tests/Cache/GenericCacheBackendUnitTestBase.php
index 97d7ccd..5ce1ab5 100644
--- a/core/modules/system/src/Tests/Cache/GenericCacheBackendUnitTestBase.php
+++ b/core/modules/system/src/Tests/Cache/GenericCacheBackendUnitTestBase.php
@@ -485,7 +485,7 @@ function testDeleteTags() {
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2'), 'Two cache items were created.');
 
     // Delete test_tag of value 1. This should delete both entries.
-    $backend->deleteTags(array('test_tag:2'));
+    Cache::deleteTags(array('test_tag:2'));
     $this->assertFalse($backend->get('test_cid_invalidate1') || $backend->get('test_cid_invalidate2'), 'Two cache items invalidated after deleting a cache tag.');
     $this->assertFalse($backend->get('test_cid_invalidate1', TRUE) || $backend->get('test_cid_invalidate2', TRUE), 'Two cache items deleted after deleting a cache tag.');
 
@@ -495,7 +495,7 @@ function testDeleteTags() {
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2'), 'Two cache items were created.');
 
     // Delete test_tag of value 1. This should delete both entries.
-    $backend->deleteTags(array('test_tag:1'));
+    Cache::deleteTags(array('test_tag:1'));
     $this->assertFalse($backend->get('test_cid_invalidate1') || $backend->get('test_cid_invalidate2'), 'Two cache items invalidated after deleted a cache tag.');
     $this->assertFalse($backend->get('test_cid_invalidate1', TRUE) || $backend->get('test_cid_invalidate2', TRUE), 'Two cache items deleted after deleting a cache tag.');
 
@@ -504,7 +504,7 @@ function testDeleteTags() {
     $backend->set('test_cid_invalidate2', $this->defaultValue, Cache::PERMANENT, array('test_tag:2'));
     $backend->set('test_cid_invalidate3', $this->defaultValue, Cache::PERMANENT, array('test_tag_foo:3'));
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2') && $backend->get('test_cid_invalidate3'), 'Three cached items were created.');
-    $backend->deleteTags(array('test_tag_foo:3'));
+    Cache::deleteTags(array('test_tag_foo:3'));
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2'), 'Cached items not matching the tag were not deleted.');
     $this->assertFalse($backend->get('test_cid_invalidated3', TRUE), 'Cache item matching the tag was deleted.');
 
@@ -518,10 +518,7 @@ function testDeleteTags() {
       $this->assertTrue($this->getCacheBackend($bin)->get('test'), 'Cache item was set in bin.');
     }
 
-    // Delete tag in mulitple bins.
-    foreach ($bins as $bin) {
-      $this->getCacheBackend($bin)->deleteTags(array('test_tag:2'));
-    }
+    Cache::deleteTags(array('test_tag:2'));
 
     // Test that cache entry has been deleted in multple bins.
     foreach ($bins as $bin) {
@@ -597,7 +594,7 @@ function testInvalidateTags() {
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2'), 'Two cache items were created.');
 
     // Invalidate test_tag of value 1. This should invalidate both entries.
-    $backend->invalidateTags(array('test_tag:2'));
+    Cache::invalidateTags(array('test_tag:2'));
     $this->assertFalse($backend->get('test_cid_invalidate1') || $backend->get('test_cid_invalidate2'), 'Two cache items invalidated after invalidating a cache tag.');
     $this->assertTrue($backend->get('test_cid_invalidate1', TRUE) && $backend->get('test_cid_invalidate2', TRUE), 'Cache items not deleted after invalidating a cache tag.');
 
@@ -607,7 +604,7 @@ function testInvalidateTags() {
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2'), 'Two cache items were created.');
 
     // Invalidate test_tag of value 1. This should invalidate both entries.
-    $backend->invalidateTags(array('test_tag:1'));
+    Cache::invalidateTags(array('test_tag:1'));
     $this->assertFalse($backend->get('test_cid_invalidate1') || $backend->get('test_cid_invalidate2'), 'Two caches removed after invalidating a cache tag.');
     $this->assertTrue($backend->get('test_cid_invalidate1', TRUE) && $backend->get('test_cid_invalidate2', TRUE), 'Cache items not deleted after invalidating a cache tag.');
 
@@ -616,7 +613,7 @@ function testInvalidateTags() {
     $backend->set('test_cid_invalidate2', $this->defaultValue, Cache::PERMANENT, array('test_tag:2'));
     $backend->set('test_cid_invalidate3', $this->defaultValue, Cache::PERMANENT, array('test_tag_foo:3'));
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2') && $backend->get('test_cid_invalidate3'), 'Three cached items were created.');
-    $backend->invalidateTags(array('test_tag_foo:3'));
+    Cache::invalidateTags(array('test_tag_foo:3'));
     $this->assertTrue($backend->get('test_cid_invalidate1') && $backend->get('test_cid_invalidate2'), 'Cache items not matching the tag were not invalidated.');
     $this->assertFalse($backend->get('test_cid_invalidated3'), 'Cached item matching the tag was removed.');
 
@@ -630,10 +627,7 @@ function testInvalidateTags() {
       $this->assertTrue($this->getCacheBackend($bin)->get('test'), 'Cache item was set in bin.');
     }
 
-    // Invalidate tag in mulitple bins.
-    foreach ($bins as $bin) {
-      $this->getCacheBackend($bin)->invalidateTags(array('test_tag:2'));
-    }
+    Cache::invalidateTags(array('test_tag:2'));
 
     // Test that cache entry has been invalidated in multple bins.
     foreach ($bins as $bin) {
diff --git a/core/modules/system/src/Tests/Cache/MemoryBackendUnitTest.php b/core/modules/system/src/Tests/Cache/MemoryBackendUnitTest.php
index 85edfde..3a99482 100644
--- a/core/modules/system/src/Tests/Cache/MemoryBackendUnitTest.php
+++ b/core/modules/system/src/Tests/Cache/MemoryBackendUnitTest.php
@@ -23,6 +23,8 @@ class MemoryBackendUnitTest extends GenericCacheBackendUnitTestBase {
    *   A new MemoryBackend object.
    */
   protected function createCacheBackend($bin) {
-    return new MemoryBackend($bin);
+    $backend = new MemoryBackend($bin);
+    \Drupal::service('cache_tags')->addHandler($backend);
+    return $backend;
   }
 }
diff --git a/core/modules/system/src/Tests/Cache/PhpBackendUnitTest.php b/core/modules/system/src/Tests/Cache/PhpBackendUnitTest.php
index 57df19b..01b58ca 100644
--- a/core/modules/system/src/Tests/Cache/PhpBackendUnitTest.php
+++ b/core/modules/system/src/Tests/Cache/PhpBackendUnitTest.php
@@ -23,7 +23,9 @@ class PhpBackendUnitTest extends GenericCacheBackendUnitTestBase {
    *   A new MemoryBackend object.
    */
   protected function createCacheBackend($bin) {
-    return new PhpBackend($bin);
+    $backend = new PhpBackend($bin);
+    \Drupal::service('cache_tags')->addHandler($backend);
+    return $backend;
   }
 
 }