diff --git a/README.md b/README.md
index 7cc52667..64429ffb 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,7 @@ For this project, we're using:
 * We use ES6
 * We don't use ES6's class declaration for React components because it does not support Mixins as well as Autobinding ([Blog post about it](http://facebook.github.io/react/blog/2015/01/27/react-v0.13.0-beta-1.html#autobinding))
 * We don't use camel case for file naming but in everything Javascript related
+* We use `let` instead of `var`: [SA Post](http://stackoverflow.com/questions/762011/javascript-let-keyword-vs-var-keyword) 
 
 
 Reading list
diff --git a/js/components/ascribe_app.js b/js/components/ascribe_app.js
index f5ff7c93..ead715f9 100644
--- a/js/components/ascribe_app.js
+++ b/js/components/ascribe_app.js
@@ -2,8 +2,8 @@ import React from 'react';
 import Router from 'react-router';
 
 
-var Link = Router.Link;
-var RouteHandler = Router.RouteHandler;
+let Link = Router.Link;
+let RouteHandler = Router.RouteHandler;
 
 
 class AscribeApp extends React.Component {
diff --git a/js/components/piece_list.js b/js/components/piece_list.js
index 516ad62e..6c85efb3 100644
--- a/js/components/piece_list.js
+++ b/js/components/piece_list.js
@@ -6,7 +6,7 @@ import PieceListActions from '../actions/piece_list_actions';
 
 let Link = Router.Link;
 
-var PieceList = React.createClass({
+let PieceList = React.createClass({
     getInitialState() {
         return PieceListStore.getState();
     },
diff --git a/js/constants/application_constants.js b/js/constants/application_constants.js
index 982a5373..8efb7196 100644
--- a/js/constants/application_constants.js
+++ b/js/constants/application_constants.js
@@ -1,4 +1,4 @@
-var constants = {
+let constants = {
     'baseUrl': 'http://staging.ascribe.io/api/',
     'debugCredentialBase64': 'ZGltaUBtYWlsaW5hdG9yLmNvbTowMDAwMDAwMDAw' // dimi@mailinator:0000000000
 };
diff --git a/js/fetchers/piece_list_fetcher.js b/js/fetchers/piece_list_fetcher.js
index 133070fd..4e4b7567 100644
--- a/js/fetchers/piece_list_fetcher.js
+++ b/js/fetchers/piece_list_fetcher.js
@@ -3,7 +3,7 @@ import fetch from 'isomorphic-fetch';
 import AppConstants from '../constants/application_constants';
 import FetchApiUtils from '../utils/fetch_api_utils';
 
-var PieceListFetcher = {
+let PieceListFetcher = {
     /**
      * Fetches a list of pieces from the API.
      * Can be called with all supplied queryparams the API.
diff --git a/js/routes.js b/js/routes.js
index 2aa89bc2..b093f79c 100644
--- a/js/routes.js
+++ b/js/routes.js
@@ -5,9 +5,9 @@ import AscribeApp from './components/ascribe_app';
 import PieceList from './components/piece_list';
 import Piece from './components/piece';
 
-var Route = Router.Route;
+let Route = Router.Route;
 
-var routes = (
+let routes = (
     <Route name="app" path="/" handler={AscribeApp}>
         <Route name="pieces" handler={PieceList} />
             <Route name="piece" path="/artworks/:bitcoin_ID_noPrefix" handler={Piece} />