diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index c7094af..bd1612b 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1118,7 +1118,7 @@ function drupal_page_get_cache($check_only = FALSE) {
   }
 
   if (drupal_page_is_cacheable()) {
-    $cache = cache('page')->get($base_root . request_uri());
+    $cache = cache('page')->get($base_root . drupal_page_cache_key() . request_uri());
     if ($cache !== FALSE) {
       $cache_hit = TRUE;
     }
@@ -1126,6 +1126,12 @@ function drupal_page_get_cache($check_only = FALSE) {
   }
 }
 
+function drupal_page_cache_key() {
+  $key = array();
+  $key[] = Drupal::request()->createFromGlobals()->getRequestFormat();
+  return md5(implode(',', $key));
+}
+
 /**
  * Determines the cacheability of the current page.
  *