diff --git a/wp-admin/admin-ajax.php b/wp-admin/admin-ajax.php
index 85a686ed2..0fbf0d52f 100644
--- a/wp-admin/admin-ajax.php
+++ b/wp-admin/admin-ajax.php
@@ -860,8 +860,7 @@ case 'add-meta' :
 			'supplemental' => array('postid' => $pid)
 		) );
 	} else { // Update?
-		$var_by_ref = array_keys( $_POST['meta'] );
-		$mid = (int) array_pop( $var_by_ref );
+		$mid = (int) key( $_POST['meta'] );
 		$key = stripslashes( $_POST['meta'][$mid]['key'] );
 		$value = stripslashes( $_POST['meta'][$mid]['value'] );
 		if ( '' == trim($key) )