diff --git a/manifest.php b/manifest.php
index 446e74f..4ea70c4 100644
--- a/manifest.php
+++ b/manifest.php
@@ -4,15 +4,14 @@
  *
  * The dynamic manifest file is constructed here
  */
-
-/* Load WordPress */
-include_once( $_SERVER['DOCUMENT_ROOT'] . '/wp-load.php' );
+$session = session_id();
+if ( empty( $session ) ) session_start();
 
 header( 'Content-Type: text/cache-manifest' );
 
 echo 'CACHE MANIFEST
 
-# version ' . get_option( '_wp_appcache_manifest_timestamp' ) . ' v1
+# version ' . $_SESSION['wp_appcache_manifest_timestamp'] . ' v1
 
 CACHE:
 
diff --git a/wp-appcache.php b/wp-appcache.php
index 3b50d53..4a39060 100644
--- a/wp-appcache.php
+++ b/wp-appcache.php
@@ -29,6 +29,11 @@ function wp_appcache_add_manifest() {
 		if ( ! is_user_logged_in() ) {
 			add_filter( 'language_attributes', 'wp_appcache_add_manifest_to_language_attributes' );
 
+			// Set the timestamp as a session variable
+			$session = session_id();
+			if ( empty( $session ) ) session_start();
+			$_SESSION['wp_appcache_manifest_timestamp'] = get_option( '_wp_appcache_manifest_timestamp' );
+
 			function wp_appcache_add_manifest_to_language_attributes( $output ) {
 				return $output . ' manifest="' . plugins_url( 'manifest.php', __FILE__ ) . '"';
 			}