diff --git a/action.php b/action.php
index 23c662d..2615e59 100644
--- a/action.php
+++ b/action.php
@@ -16,7 +16,7 @@
 class action_plugin_googlefonts extends DokuWiki_Action_Plugin {
 
     // register hook
-    function register(&$controller) {
+    function register(Doku_Event_Handler $controller) {
         $controller->register_hook('TPL_METAHEADER_OUTPUT','BEFORE', $this, '_addFontCode');
     }