diff --git a/core/modules/page_cache/src/Tests/PageCacheStorageResponseTest.php b/core/modules/page_cache/src/Tests/PageCacheStorageResponseTest.php
new file mode 100644
index 0000000..b3dfcea
--- /dev/null
+++ b/core/modules/page_cache/src/Tests/PageCacheStorageResponseTest.php
@@ -0,0 +1,118 @@
+<?php
+
+namespace Drupal\page_cache\Tests;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Cache\CacheableResponse;
+use Drupal\Core\PageCache\RequestPolicyInterface;
+use Drupal\Core\PageCache\ResponsePolicyInterface;
+use Drupal\Tests\UnitTestCase;
+use Drupal\page_cache\StackMiddleware\PageCache;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+/**
+ * @coversDefaultClass \Drupal\page_cache\StackMiddleware\PageCache
+ * @group page_cache
+ */
+class PageCacheStorageResponseTest extends UnitTestCase {
+
+  /**
+   * The cache backend used in the test.
+   *
+   * @var \Drupal\Core\Cache\CacheBackendInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $cache;
+
+  /**
+   * The mocked HTTP kernel.
+   *
+   * @var \Symfony\Component\HttpKernel\HttpKernelInterface|PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $kernel;
+
+  /**
+   * The accessible reflection of the tested protected method.
+   *
+   * @var \ReflectionMethod
+   */
+  protected $method;
+
+  /**
+   * The mocked request policy.
+   *
+   * @var \Drupal\Core\PageCache\RequestPolicyInterface|PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $requestPolicy;
+
+  /**
+   * The mocked response policy.
+   *
+   * @var \Drupal\Core\PageCache\ResponsePolicyInterface|PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $responsePolicy;
+
+  /**
+   * The tested page cache middleware.
+   *
+   * @var \Drupal\page_cache\StackMiddleware\PageCache
+   */
+  protected $pageCache;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    $this->cache = $this->getMock(CacheBackendInterface::class);
+    $this->kernel = $this->getMock(HttpKernelInterface::class);
+    $this->requestPolicy = $this->getMock(RequestPolicyInterface::class);
+    $this->responsePolicy = $this->getMock(ResponsePolicyInterface::class);
+
+    $this->pageCache = new PageCache(
+      $this->kernel,
+      $this->cache,
+      $this->requestPolicy,
+      $this->responsePolicy
+    );
+
+    $this->method = new \ReflectionMethod(PageCache::class, 'storeResponse');
+    $this->method->setAccessible(TRUE);
+  }
+
+  /**
+   * Tests that storeResponse method works in general without any data manipulations.
+   */
+  public function testSimpleInvocation() {
+    $request = new Request();
+    $response = new CacheableResponse();
+
+    // Expect backend cache to be set.
+    $this->cache->expects($this->once())->method('set');
+
+    $this->assertTrue($this->method->invoke($this->pageCache, $request, $response));
+  }
+
+  /**
+   * Tests handling of NULL value returned from Response::getExpires.
+   */
+  public function testResponseWithoutExpiresHeader() {
+    $request = new Request();
+
+    $this->cache->expects($this->exactly(2))->method('set');
+
+    $response = $this->getMock(CacheableResponse::class, ['getExpires']);
+    $response->expects($this->once())
+      ->method('getExpires')
+      ->will($this->returnValue(new \DateTime()));
+
+    $this->assertTrue($this->method->invoke($this->pageCache, $request, $response));
+
+    $response = $this->getMock(CacheableResponse::class, ['getExpires']);
+    $response->expects($this->once())
+      ->method('getExpires')
+      ->will($this->returnValue(NULL));
+
+    $this->assertTrue($this->method->invoke($this->pageCache, $request, $response));
+  }
+
+}