diff --git a/includes/common.inc b/includes/common.inc
index 34fa9b9..f2ec788 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -5278,6 +5278,12 @@ function drupal_page_set_cache() {
   global $base_root;
 
   if (drupal_page_is_cacheable()) {
+    if (variable_get('cache_lifetime', 0)) {
+      $expire = REQUEST_TIME + variable_get('cache_lifetime', 0);
+    }
+    else {
+      $expire = CACHE_TEMPORARY;
+    }
 
     // Check whether the current page might be compressed.
     $page_compressed = variable_get('page_compression', TRUE) && extension_loaded('zlib');
@@ -5293,7 +5299,7 @@ function drupal_page_set_cache() {
         // because by the time it is read, the configuration might change.
         'page_compressed' => $page_compressed,
       ),
-      'expire' => CACHE_TEMPORARY,
+      'expire' => $expire,
       'created' => REQUEST_TIME,
     );