SyntaxError: Use of const in strict mode. Have latest node

I'm trying to start my node app, but I keep getting error:

SyntaxError: Use of const in strict mode.

/var/www/server/server/node_modules/ws/index.js:9
const WebSocket = require('./lib/WebSocket');
^^^^^
SyntaxError: Use of const in strict mode.
    at exports.runInThisContext (vm.js:73:16)
    at Module._compile (module.js:443:25)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/var/www/server/server/site.js:9:17)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)

My NPM version is 4.2.0 and my Node version is v.0.12.18

via Omar Lers