diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index c2bb1b4..ef5c14c 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -900,26 +900,23 @@ function drupal_serve_page_from_cache(Response $response, Request $request) {
   }
 
   // Perform HTTP revalidation.
+  // @todo Use Response::isNotModified() as per https://drupal.org/node/2259489
   $last_modified = $response->getLastModified();
   if ($last_modified) {
     // See if the client has provided the required HTTP headers.
     $if_modified_since = $request->server->has('HTTP_IF_MODIFIED_SINCE') ? strtotime($request->server->get('HTTP_IF_MODIFIED_SINCE')) : FALSE;
     $if_none_match = $request->server->has('HTTP_IF_NONE_MATCH') ? stripslashes($request->server->get('HTTP_IF_NONE_MATCH')) : FALSE;
 
-    $last_modified_match = $if_modified_since === $last_modified->getTimestamp();
-    $etag_match = $if_none_match == $response->getEtag();
-
-    if (($if_modified_since && $if_none_match && $last_modified_match && $etag_match) // If both revalidation request headers are present, apply both.
-        || ($if_modified_since && !$if_none_match && $last_modified_match) // Only Last-Modified must match.
-        || ($if_none_match && !$if_modified_since && $etag_match) // Only ETag must match.
-    ) {
+    if ($if_modified_since && $if_none_match
+      && $if_none_match == $response->getEtag() // etag must match
+      && $if_modified_since == $last_modified->getTimestamp()) {  // if-modified-since must match
       $response->setStatusCode(304);
       $response->setContent(NULL);
 
       // In the case of a 304 response, certain headers must be sent, and the
       // remaining may not (see RFC 2616, section 10.3.5).
       foreach (array_keys($response->headers->all()) as $name) {
-        if (!in_array($name, array('etag', 'content-location', 'expires', 'cache-control', 'vary'))) {
+        if (!in_array($name, array('content-location', 'expires', 'cache-control', 'vary'))) {
           $response->headers->remove($name);
         }
       }
diff --git a/core/includes/common.inc b/core/includes/common.inc
index 963f4dd..1f8e387 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -2830,13 +2830,8 @@ function drupal_page_set_cache(Response $response, Request $request) {
   }
 
   // Use the actual timestamp from an Expires header, if available.
-  $expire = Cache::PERMANENT;
-  if ($response->headers->has('Expires')) {
-    $timestamp = $response->getExpires()->getTimestamp();
-    if ($timestamp > REQUEST_TIME) {
-      $expire = $timestamp;
-    }
-  }
+  $date = $response->getExpires();
+  $expire = ($date > (new DateTime())) ? $date->getTimestamp() : Cache::PERMANENT;
 
   $cid = drupal_page_cache_get_cid($request);
   $tags = HtmlViewSubscriber::convertHeaderToCacheTags($response->headers->get('X-Drupal-Cache-Tags'));
diff --git a/core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php
index a96b478..616f3fd 100644
--- a/core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php
@@ -15,8 +15,8 @@
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
-use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
@@ -85,8 +85,10 @@ public function onRespond(FilterResponseEvent $event) {
 
     // Add headers necessary to specify whether the response should be cached by
     // proxies and/or the browser.
-    if ($is_cacheable && $this->config->get('cache.page.max_age') > 0 && !$this->isCacheControlCustomized($response)) {
-      $this->setResponseCacheable($response, $request);
+    if ($is_cacheable && $this->config->get('cache.page.max_age') > 0) {
+      if (!$this->isCacheControlCustomized($response)) {
+        $this->setResponseCacheable($response, $request);
+      }
     }
     else {
       $this->setResponseNotCacheable($response, $request);
@@ -111,7 +113,7 @@ public function onRespond(FilterResponseEvent $event) {
    * explicitly.
    *
    * When neither Cache-Control nor any of the ETag, Last-Modified, Expires
-   * headers are set on the response, ::get('cache-control') returns the value
+   * headers are set on the response, ::get('Cache-Control') returns the value
    * 'no-cache'. If any of ETag, Last-Modified or Expires are set but not
    * Cache-Control, then 'private, must-revalidate' (in exactly this order) is
    * returned.
@@ -124,7 +126,7 @@ public function onRespond(FilterResponseEvent $event) {
    *   TRUE when Cache-Control header was set explicitely on the given response.
    */
   protected function isCacheControlCustomized(Response $response) {
-    $cache_control = $response->headers->get('cache-control');
+    $cache_control = $response->headers->get('Cache-Control');
     return $cache_control != 'no-cache' && $cache_control != 'private, must-revalidate';
   }
 
@@ -203,7 +205,7 @@ protected function setResponseCacheable(Response $response, Request $request) {
    *   A response object.
    */
   protected function setCacheControlNoCache(Response $response) {
-    $response->headers->set('cache-control', 'no-cache, must-revalidate, post-check=0, pre-check=0');
+    $response->headers->set('Cache-Control', 'no-cache, must-revalidate, post-check=0, pre-check=0');
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Bootstrap/PageCacheTest.php b/core/modules/system/lib/Drupal/system/Tests/Bootstrap/PageCacheTest.php
index 150e1db..fdf16b9 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Bootstrap/PageCacheTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Bootstrap/PageCacheTest.php
@@ -128,40 +128,21 @@ function testConditionalRequests() {
 
     $this->drupalGet('', array(), array('If-Modified-Since: ' . $last_modified, 'If-None-Match: ' . $etag));
     $this->assertResponse(304, 'Conditional request returned 304 Not Modified.');
-    $this->assertTrue(strlen($this->drupalGetContent()) == 0, 'No HTML returned.');
 
     $this->drupalGet('', array(), array('If-Modified-Since: ' . gmdate(DATE_RFC822, strtotime($last_modified)), 'If-None-Match: ' . $etag));
     $this->assertResponse(304, 'Conditional request with obsolete If-Modified-Since date returned 304 Not Modified.');
-    $this->assertTrue(strlen($this->drupalGetContent()) == 0, 'No HTML returned.');
 
     $this->drupalGet('', array(), array('If-Modified-Since: ' . gmdate(DATE_RFC850, strtotime($last_modified)), 'If-None-Match: ' . $etag));
     $this->assertResponse(304, 'Conditional request with obsolete If-Modified-Since date returned 304 Not Modified.');
-    $this->assertTrue(strlen($this->drupalGetContent()) == 0, 'No HTML returned.');
 
     $this->drupalGet('', array(), array('If-Modified-Since: ' . $last_modified));
-    $this->assertResponse(304, 'Conditional request with If-Modified-Since but without If-None-Match returned 304 Not Modified.');
-    $this->assertTrue(strlen($this->drupalGetContent()) == 0, 'No HTML returned.');
-
-    $this->drupalGet('', array(), array('If-None-Match: ' . $etag));
-    $this->assertResponse(304, 'Conditional request with If-None-Match but without If-Modified-Since returned 304 Not Modified.');
-    $this->assertTrue(strlen($this->drupalGetContent()) == 0, 'No HTML returned.');
-
-    $this->drupalGet('', array(), array('If-Modified-Since: ' . gmdate(DATE_RFC1123, strtotime($last_modified) + 1), 'If-None-Match: ' . $etag));
-    $this->assertResponse(200, 'Conditional request with an If-Modified-Since date newer than Last-Modified returned 200 OK.');
-    // Verify the page is not printed twice when the cache is warm.
-    $this->assertNoPattern('#<html.*<html#');
-    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
-
-    $this->drupalGet('', array(), array('If-Modified-Since: ' . $last_modified, 'If-None-Match: ' . $etag . '-is-invalid'));
-    $this->assertResponse(200, 'Conditional request with an invalid If-None-Match ETag value returned 200 OK.');
     // Verify the page is not printed twice when the cache is warm.
     $this->assertNoPattern('#<html.*<html#');
+    $this->assertResponse(200, 'Conditional request without If-None-Match returned 200 OK.');
     $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
 
-    $this->drupalGet('', array(), array('If-Modified-Since: ' . gmdate(DATE_RFC1123, strtotime($last_modified) + 1), 'If-None-Match: ' . $etag . '-is-invalid'));
-    $this->assertResponse(200, 'Conditional request with an If-Modified-Since date nwer than Last-Modified and an invalid If-None-Match ETag value returned 200 OK.');
-    // Verify the page is not printed twice when the cache is warm.
-    $this->assertNoPattern('#<html.*<html#');
+    $this->drupalGet('', array(), array('If-Modified-Since: ' . gmdate(DATE_RFC1123, strtotime($last_modified) + 1), 'If-None-Match: ' . $etag));
+    $this->assertResponse(200, 'Conditional request with new a If-Modified-Since date newer than Last-Modified returned 200 OK.');
     $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
 
     $user = $this->drupalCreateUser();