diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index a05abea..e46368c 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -867,9 +867,26 @@ function drupal_page_header() {
  * response is sent.
  */
 function drupal_serve_page_from_cache(Response $response, Request $request) {
+  // Only allow caching in the browser and prevent that the response is stored
+  // by an external proxy server when the following conditions apply:
+  // 1. There is a session cookie on the request.
+  // 2. The Vary: Cookie header is on the response.
+  // 3. The Cache-Control header does not contain the no-cache directive.
+  if ($request->cookies->has(session_name()) &&
+    in_array('Cookie', $response->getVary()) &&
+    !$response->headers->hasCacheControlDirective('no-cache')) {
+
+    $response->setPrivate();
+  }
+
   // Negotiate whether to use compression.
   if ($response->headers->get('Content-Encoding') == 'gzip' && extension_loaded('zlib')) {
-    if (strpos($request->headers->get('Accept-Encoding'), 'gzip') === FALSE) {
+    if (strpos($request->headers->get('Accept-Encoding'), 'gzip') !== FALSE) {
+      // The response content is already gzip'ed, so make sure
+      // zlib.output_compression does not compress it once more.
+      ini_set('zlib.output_compression', '0');
+    }
+    else {
       // The client does not support compression. Decompress the content and
       // remove the Content-Encoding header.
       $content = $response->getContent();
@@ -877,23 +894,6 @@ function drupal_serve_page_from_cache(Response $response, Request $request) {
       $response->setContent($content);
       $response->headers->remove('Content-Encoding');
     }
-    else {
-      // The response content is already gzip'ed, so make sure
-      // zlib.output_compression does not compress it once more.
-      ini_set('zlib.output_compression', '0');
-    }
-  }
-
-  // Prevent that the response is cached by an external proxy server and only
-  // allow it to be cached by the browser when the following conditions are met:
-  // 1. There is a session cookie on the request.
-  // 2. The Vary: Cookie header is on the response.
-  // 3. The Cache-Control header does not contain the no-cache directive.
-  if ($request->cookies->has(session_name()) &&
-    in_array('Cookie', $response->getVary()) &&
-    !$response->headers->hasCacheControlDirective('no-cache')) {
-
-    $response->setPrivate();
   }
 
   // Perform HTTP revalidation.