Index: option.php
===================================================================
--- option.php	(revision 21204)
+++ option.php	(working copy)
@@ -1021,7 +1021,11 @@
 function set_site_transient( $transient, $value, $expiration = 0 ) {
 	global $_wp_using_ext_object_cache;
 
-	$value = apply_filters( 'pre_set_site_transient_' . $transient, $value );
+	$options = apply_filters( 'pre_set_site_transient_' . $transient, $value, $expiration );
+	if ( is_string( $options ) )
+		$value = $options;
+	else
+		extract( $options, EXTR_OVERWRITE );
 
 	if ( $_wp_using_ext_object_cache ) {
 		$result = wp_cache_set( $transient, $value, 'site-transient', $expiration );