From f3354732bf95103322fa1610e64fb4c71332f199 Mon Sep 17 00:00:00 2001
From: "Shahar Or (mightyiam)" <mightyiampresence@gmail.com>
Date: Thu, 11 May 2017 11:42:25 +0300
Subject: [PATCH] fix #291

---
 src/modules/eventlisteners.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/modules/eventlisteners.ts b/src/modules/eventlisteners.ts
index 8595dba..95bc0f5 100755
--- a/src/modules/eventlisteners.ts
+++ b/src/modules/eventlisteners.ts
@@ -2,7 +2,7 @@ import {VNode, VNodeData} from '../vnode';
 import {Module} from './module';
 
 export type On = {
-  [N in keyof HTMLElementEventMap]: (ev: HTMLElementEventMap[N]) => void
+  [N in keyof HTMLElementEventMap]?: (ev: HTMLElementEventMap[N]) => void
 } & {
   [event: string]: EventListener
 };