Index: wp-includes/option.php
===================================================================
--- wp-includes/option.php	(revision 21204)
+++ wp-includes/option.php	(working copy)
@@ -1022,6 +1022,7 @@
 	global $_wp_using_ext_object_cache;
 
 	$value = apply_filters( 'pre_set_site_transient_' . $transient, $value );
+	$expiration = apply_filters( 'pre_set_site_transient_exp_' . $transient, $expiration );
 
 	if ( $_wp_using_ext_object_cache ) {
 		$result = wp_cache_set( $transient, $value, 'site-transient', $expiration );