diff --git a/docs/examples/preact/index.js b/docs/examples/preact/index.js
index a0e9378..1f45be4 100644
--- a/docs/examples/preact/index.js
+++ b/docs/examples/preact/index.js
@@ -18,8 +18,8 @@ const Fibonacci = Stateful({
   getInitialState: () => ({index: 0}),
 
   handlers: {
-    prev: ({index}) => ({index: index - 1}),
-    next: ({index}) => ({index: index + 1}),
+    prev: ({index}, event) => ({index: index - 1}),
+    next: ({index}, event) => ({index: index + 1}),
   },
   
   render: (props, state, handlers) =>