diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index c7094af..041583c 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1110,7 +1110,6 @@ function variable_del($name) {
  *   The cache object, if the page was found in the cache, NULL otherwise.
  */
 function drupal_page_get_cache($check_only = FALSE) {
-  global $base_root;
   static $cache_hit = FALSE;
 
   if ($check_only) {
@@ -1118,7 +1117,7 @@ function drupal_page_get_cache($check_only = FALSE) {
   }
 
   if (drupal_page_is_cacheable()) {
-    $cache = cache('page')->get($base_root . request_uri());
+    $cache = cache('page')->get(drupal_page_cache_key());
     if ($cache !== FALSE) {
       $cache_hit = TRUE;
     }
@@ -1126,6 +1125,15 @@ function drupal_page_get_cache($check_only = FALSE) {
   }
 }
 
+function drupal_page_cache_key() {
+  global $base_root;
+  $key = array($base_root);
+  $request = Drupal::request()->createFromGlobals();
+  $key[] = Drupal::service('content_negotiation')->getContentType($request);
+  $key[] = request_uri();
+  return md5(implode(',', $key));
+}
+
 /**
  * Determines the cacheability of the current page.
  *
diff --git a/core/includes/common.inc b/core/includes/common.inc
index 654d849..b62ce72 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -4647,7 +4647,7 @@ function drupal_page_set_cache($body) {
 
   if (drupal_page_is_cacheable()) {
     $cache = (object) array(
-      'cid' => $base_root . request_uri(),
+      'cid' => drupal_page_cache_key(),
       'data' => array(
         'path' => current_path(),
         'body' => $body,