diff --git a/addons/viewport/src/manager.jsx b/addons/viewport/src/manager.jsx
index 76de2c8473e..c60164f1246 100644
--- a/addons/viewport/src/manager.jsx
+++ b/addons/viewport/src/manager.jsx
@@ -6,7 +6,7 @@ import { Panel } from './components/Panel';
 const ADDON_ID = 'storybook-addon-viewport';
 const PANEL_ID = `${ADDON_ID}/addon-panel`;
 
-function addChannel(api) {
+const addChannel = (api) => {
   const channel = addons.getChannel();
 
   addons.addPanel(PANEL_ID, {
@@ -17,7 +17,7 @@ function addChannel(api) {
   });
 }
 
-function init() {
+const init = () => {
   addons.register(ADDON_ID, addChannel);
 }