diff --git a/core/lib/Drupal/Core/Cache/CacheItem.php b/core/lib/Drupal/Core/Cache/CacheItem.php
index b9d1704ffc..e0fcb86253 100644
--- a/core/lib/Drupal/Core/Cache/CacheItem.php
+++ b/core/lib/Drupal/Core/Cache/CacheItem.php
@@ -132,7 +132,7 @@ public function isExpired() {
       return FALSE;
     }
     else {
-      return time() >= $_SERVER['REQUEST_TIME'];
+      return \Drupal::time()->getCurrentTime() >= $this->expire;
     }
   }
 
diff --git a/core/tests/Drupal/Tests/Core/Cache/CacheItemTest.php b/core/tests/Drupal/Tests/Core/Cache/CacheItemTest.php
new file mode 100644
index 0000000000..956208a76b
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Cache/CacheItemTest.php
@@ -0,0 +1,81 @@
+<?php
+
+namespace Drupal\Tests\Core\Cache;
+
+use Drupal\Component\Datetime\TimeInterface;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Cache\CacheItem;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Cache\CacheItem
+ * @group Cache
+ */
+class CacheItemTest extends UnitTestCase {
+
+  /**
+   * Test that the constructor fills in all properties.
+   *
+   * @covers ::__construct
+   * @covers ::getKey
+   * @covers ::getCreationTimestamp
+   * @covers ::getData
+   * @covers ::getExpirationTimestamp
+   * @covers ::getTags
+   * @covers ::isValid
+   */
+  public function testItem() {
+    $cache_item = new CacheItem('foo', ['animals' => 'owls']);
+    $this->assertSame('foo', $cache_item->cid);
+    $this->assertSame('foo', $cache_item->getKey());
+    $this->assertSame(0, $cache_item->created);
+    $this->assertSame(0, $cache_item->getCreationTimestamp());
+    $this->assertSame(['animals' => 'owls'], $cache_item->data);
+    $this->assertSame(['animals' => 'owls'], $cache_item->getData());
+    $this->assertSame(CacheBackendInterface::CACHE_PERMANENT, $cache_item->expire);
+    $this->assertSame(CacheBackendInterface::CACHE_PERMANENT, $cache_item->getExpirationTimestamp());
+    $this->assertSame([], $cache_item->tags);
+    $this->assertSame([], $cache_item->getTags());
+    $this->assertFalse($cache_item->valid);
+    $this->assertFalse($cache_item->isValid());
+  }
+
+  /**
+   * Tests the isExpired method.
+   *
+   * @param int $expire
+   *   The expiration time.
+   * @param bool $expected
+   *   A boolean to indicate if the item should be expired.
+   *
+   * @covers ::isExpired
+   * @dataProvider provideExpirationData
+   */
+  public function testExpiration($expire, $expected) {
+    $time_service = $this->prophesize(TimeInterface::class);
+    $time_service->getCurrentTime()->willReturn(200);
+
+    $container = new ContainerBuilder();
+    $container->set('datetime.time', $time_service->reveal());
+    \Drupal::setContainer($container);
+
+    $cache_item = new CacheItem('bar', 'More owls', $expire);
+    $this->assertSame($expected, $cache_item->isExpired());
+  }
+
+  /**
+   * Provides test data.
+   *
+   * @return array
+   */
+  public function provideExpirationData() {
+    return [
+      [CacheBackendInterface::CACHE_PERMANENT, FALSE],
+      [CacheBackendInterface::CACHE_PERMANENT, FALSE],
+      [10, TRUE],
+      [1000, FALSE],
+    ];
+  }
+
+}