diff --git a/syntax.php b/syntax.php
index 5c96086..8e89e61 100644
--- a/syntax.php
+++ b/syntax.php
@@ -56,7 +56,7 @@ public function connectTo($mode) {
      * 
      * @return array
      */
-    public function handle($match, $state, $pos, &$handler) {
+    public function handle($match, $state, $pos, Doku_Handler $handler) {
         return array($match, $state, $pos);
     }
     
@@ -69,7 +69,7 @@ public function handle($match, $state, $pos, &$handler) {
      * 
      * @return type boolean is de operatie geslaagd?
      */
-    public function render($format, &$renderer, $data) {
+    public function render($format, Doku_Renderer $renderer, $data) {
         
         if('xhtml' === $format) {
             try {